Three-dimensional packaging structure and forming method thereof

Abstract

The invention relates to a three-dimensional packaging structure and a forming method thereof. The three-dimensional packaging structure comprises a substrate, wherein the substrate comprises a front surface and a back surface which are oppositely distributed; the chip is mounted on the front surface of the substrate; the inductor is positioned on one side, deviating from the substrate, of the chip; the conductive connection structure is located on the front face of the substrate, the bottom end of the conductive connection structure is electrically connected with the substrate, the top end of the conductive connection structure is electrically connected with the inductor, the bottom end of the conductive connection structure is provided with an exhaust groove, and the exhaust groove at least extends to the edge of the conductive connection structure. According to the three-dimensional packaging structure, the coplanar problem between the conductive connection structure and the plastic packaging layer is eliminated, so that the welding quality of the inductor and the conductive connection structure is ensured, and the improvement of the performance and the manufacturing yield of the three-dimensional packaging structure is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuit manufacturing, and in particular to a three-dimensional packaging structure and a forming method thereof. Background Art

[0002] The power management chip is responsible for the management of power such as conversion, distribution and detection of electric energy in electronic equipment. The power management chip is indispensable to the electronic system, and its performance has a direct impact on the performance of the whole machine. The power management chip includes a substrate, a chip mounted on the substrate, and an inductor located above the chip, and the inductor is electrically connected to the substrate through a larger conductive connection structure (such as a larger copper column). In order to achieve a stable connection between the larger conductive connection structure and the substrate, more solder paste is usually arranged between the conductive connection structure and the substrate, but this leads to more voids between the conductive connection structure and the substrate after the reflow soldering process. In the subsequent plastic encapsulation process, the gas in the cavity at the bottom of the conductive connection structure expands due to heat, which will push the conductive connection structure to move upward, thereby causing the conductive connection structure to be non-coplanar with the plastic encapsulation layer. The non-coplanarity of the conductive connection structure and the plastic encapsulation layer will affect the welding quality of the inductor, and then affect the performance and manufacturing yield of the entire three-dimensional packaging structure.

[0003] Therefore, how to prevent the conductive connection structure from being non-coplanar with the plastic packaging layer, thereby ensuring the quality of inductor welding and improving the performance and manufacturing yield of the three-dimensional packaging structure, is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present invention provides a three-dimensional packaging structure and a method for forming the same, which are used to prevent the occurrence of a problem in which a conductive connection structure and a plastic packaging layer are not coplanar, thereby ensuring the quality of inductor welding and improving the performance and manufacturing yield of the three-dimensional packaging structure.

[0005] According to some embodiments, the present invention provides a three-dimensional packaging structure, comprising:

[0006] A substrate, the substrate comprising a front surface and a back surface that are oppositely distributed;

[0007] A chip is mounted on the front side of the substrate;

[0008] an inductor, located at a side of the chip facing away from the substrate;

[0009] A conductive connection structure is located on the front side of the substrate, and the bottom end of the conductive connection structure is electrically connected to the substrate, and the top end is electrically connected to the inductor. The bottom end of the conductive connection structure has an exhaust groove, and the exhaust groove extends at least to the edge of the conductive connection structure.

[0010] In some embodiments, the exhaust groove comprises:

[0011] A first groove is located on the bottom surface of the conductive connection structure facing the substrate;

[0012] The second trench is located on a side surface of the conductive connection structure, and the second trench is connected to the first trench.

[0013] In some embodiments, the conductive connection structure has a plurality of first grooves on the bottom surface facing the substrate, and each of the first grooves penetrates the bottom surface of the conductive connection structure in a direction parallel to the front surface of the substrate, the plurality of first grooves are interconnected, and at least two of the first grooves intersect.

[0014] In some embodiments, the conductive connection structure has two perpendicularly intersecting first grooves on the bottom surface facing the substrate, and opposite ends of each first groove are connected to one of the second grooves respectively.

[0015] In some embodiments, the second groove is an inverted V-shaped groove, and the width of the bottom surface of the inverted V-shaped groove is the same as the width of the first groove.

[0016] In some embodiments, the front surface of the substrate has a conductive bump; the conductive connection structure includes:

[0017] A column body is located on the front surface of the substrate, the first groove is located on the bottom surface of the column body facing the substrate, and the second groove is located on the side surface of the column body;

[0018] The wing portion is protrudingly disposed on the side surface of the column body and is electrically connected to the conductive bump.

[0019] In some embodiments, the plurality of conductive bumps are symmetrically distributed around the periphery of the column body, the wing portions are distributed around the side surfaces of the column body, and the wing portions are in contact with the plurality of conductive bumps toward the bottom surface of the substrate.

[0020] In some embodiments, in a direction perpendicular to the front surface of the substrate, a top end of the second groove is higher than the side wing portion.

[0021] In some embodiments, it also includes:

[0022] The solder layer is located at least between the column body and the front surface of the substrate. The solder layer includes a plurality of solder beads. The height of the conductive bump is greater than twice the diameter of the solder beads. The distance between the column body and the front surface of the substrate is greater than the diameter of the solder beads.

[0023] In some embodiments, the material of the column body and the material of the wing portion are both copper.

[0024] In some embodiments, it also includes:

[0025] The plastic encapsulation layer is located on the front side of the substrate. The plastic encapsulation layer at least encapsulates the chip and the conductive connection structure. The surface of the plastic encapsulation layer facing away from the substrate is flush with the surface of the conductive connection structure facing away from the substrate.

[0026] According to some other embodiments, the present invention further provides a method for forming a three-dimensional packaging structure, comprising the following steps:

[0027] Providing a substrate, the substrate comprising a front surface and a back surface that are oppositely distributed;

[0028] Mounting a chip on the front side of the substrate;

[0029] Welding a conductive connection structure on the front side of the substrate, wherein the bottom end of the conductive connection structure is electrically connected to the substrate, the bottom end of the conductive connection structure has an exhaust groove, and the exhaust groove at least extends to the edge of the conductive connection structure;

[0030] The inductor is mounted on the side of the chip facing away from the substrate, and a plastic sealing layer is formed on the front side of the substrate to at least seal the chip and the conductive connection structure. The inductor is electrically connected to the top of the conductive connection structure, and the surface of the plastic sealing layer facing away from the substrate is flush with the surface of the conductive connection structure facing away from the substrate.

[0031] In some embodiments, the specific steps of welding the conductive connection structure on the front side of the substrate include:

[0032] forming a conductive connection structure having an exhaust groove at the bottom end, wherein the exhaust groove comprises a first groove located on the bottom surface of the conductive connection structure facing the substrate and a second groove located on the side surface of the conductive connection structure, and the second groove is connected to the first groove;

[0033] The conductive connection structure is soldered to the front side of the substrate through a solder layer.

[0034] In some embodiments, the substrate has a conductive bump on the front surface; the specific steps of forming a conductive connection structure having an exhaust groove at the bottom include:

[0035] A column body having an exhaust groove at the bottom and a wing portion protruding from the side of the column body are formed, wherein the first groove is located on the bottom surface of the column body facing the substrate, the second groove is located on the side of the column body, and the wing portion is used to be electrically connected to the conductive bump.

[0036] The three-dimensional packaging structure and the formation method thereof provided by the present invention electrically connect the substrate and the inductor through a conductive connection structure, and the bottom end of the conductive connection structure has an exhaust groove, and the exhaust groove extends at least to the edge of the conductive connection structure, so that the gas in the solder paste used for welding the conductive connection structure and the substrate can be discharged through the exhaust groove during the reflow soldering process, reducing or even avoiding the generation of voids between the conductive connection structure and the substrate, thereby avoiding the gas in the void from expanding due to heat during the subsequent plastic sealing process and pushing the conductive connection structure to move upward, eliminating the coplanarity problem between the conductive connection structure and the plastic sealing layer, that is, making the top surface of the conductive connection structure flush with the top surface of the plastic sealing layer after plastic sealing, thereby ensuring the welding quality between the inductor and the conductive connection structure, and realizing the improvement of the performance and manufacturing yield of the three-dimensional packaging structure. In addition, the present invention improves the stability of the connection between the conductive connection structure and the substrate, reduces or even avoids the tilting of the conductive connection structure, and achieves further improvement in the performance and manufacturing yield of the three-dimensional packaging structure by configuring the conductive connection structure to include a column body and a side wing portion protruding on the side of the column body, and electrically connecting the side wing portion to the conductive bump on the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a top view schematic diagram of a three-dimensional packaging structure in a specific embodiment of the present invention;

[0038] Figure 2 is a schematic cross-sectional view of a three-dimensional packaging structure in a specific embodiment of the present invention;

[0039] Figure 3 is a schematic structural diagram of a conductive connection structure at an angle in a specific embodiment of the present invention;

[0040] Figure 4 is a schematic structural diagram of the conductive connection structure in a specific embodiment of the present invention at another angle;

[0041] Figure 5 is a schematic diagram of the three-dimensional structure of a part of the substrate in a specific embodiment of the present invention;

[0042] Figure 6 is a schematic cross-sectional view of a portion of a substrate in a specific embodiment of the present invention;

[0043] Figure 7 is a schematic diagram of the relative position relationship between the substrate and the conductive connection structure in a specific embodiment of the present invention;

[0044] Figure 8 It is a flow chart of a method for forming a three-dimensional packaging structure in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0045] The specific implementation manner of the three-dimensional packaging structure and the method for forming the same provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0046] This specific embodiment provides a three-dimensional packaging structure. Figure 1 is a top view schematic diagram of a three-dimensional packaging structure in a specific embodiment of the present invention, Figure 2 is a cross-sectional schematic diagram of a three-dimensional packaging structure in a specific embodiment of the present invention, Figure 3 is a schematic diagram of the structure of the conductive connection structure at an angle in a specific embodiment of the present invention, Figure 4 FIG. 2 is a schematic diagram of the structure of the conductive connection structure in another embodiment of the present invention. Figure 1-Figure 4 As shown, the three-dimensional packaging structure includes:

[0047] A substrate 20, wherein the substrate 20 includes a front surface and a back surface that are oppositely distributed;

[0048] A chip 24 is mounted on the front surface of the substrate 20;

[0049] The inductor 10 is located on a side of the chip 24 facing away from the substrate 20;

[0050] The conductive connection structure 21 is located on the front side of the substrate 20, and the bottom end of the conductive connection structure 21 is electrically connected to the substrate 20, and the top end is electrically connected to the inductor 10. The bottom end of the conductive connection structure 21 has an exhaust groove, and the exhaust groove extends at least to the edge of the conductive connection structure 21.

[0051] Specifically, the substrate 20 includes a front side and a back side that are relatively distributed. The substrate 20 has a circuit layer, and the back side of the substrate 20 has structures such as solder balls, and the circuit layer in the substrate 20 is electrically connected to the solder balls. The chip 24 can be mounted on the front side of the substrate 20 through a metal bump 23 and electrically connected to the circuit layer in the substrate 20, so that the signal in the chip 24 can be led out through the circuit layer and the solder balls or a control signal can be transmitted to the chip 24. The conductive connection structure 21 is located on the front side of the substrate 20 and is distributed on the outside of the chip 24 along a direction parallel to the front side of the substrate 20. The inductor 10 is stacked and arranged above the chip 24 along a direction perpendicular to the front side of the substrate 20, so as to form a three-dimensional packaging structure. The end of the inductor 10 has a pad 11 electrically connected to the inductor 10, and the pad 11 is welded to the top of the conductive connection structure 21, so that the electrical connection between the inductor 10 and the substrate 20 is realized through the pad 11 and the conductive connection structure 21. A connection layer 25 is further provided between the inductor 10 and the chip 24 to achieve a fixed connection between the inductor 10 and the chip 24. In one example, the connection layer 25 includes a heat dissipation adhesive and a heat sink covering the surface of the heat dissipation adhesive to enhance the connection strength between the inductor 10 and the chip 24 while enhancing the heat dissipation performance of the three-dimensional packaging structure.

[0052] In this specific embodiment, of the two opposite ends of the conductive connection structure 21 distributed in a direction perpendicular to the front surface of the substrate 20 , the end closer to the substrate 20 is the bottom end of the conductive connection structure 21 , and the end closer to the inductor 10 is the top end of the conductive connection structure 21 . In this specific embodiment, the exhaust groove is provided at the bottom end of the conductive connection structure 21, and the exhaust groove at least extends to the edge of the conductive connection structure 21, so that the gas in the solder paste used for welding the conductive connection structure 21 and the substrate 20 can be discharged from the end of the exhaust groove through the exhaust groove during the reflow soldering process, thereby reducing or even avoiding the generation of voids between the conductive connection structure 21 and the substrate 20, thereby avoiding the gas in the void from expanding due to heat during the subsequent plastic sealing process and pushing the conductive connection structure 21 to move upward, eliminating the coplanarity problem between the conductive connection structure 21 and the plastic sealing layer, that is, the top surface of the conductive connection structure 21 after plastic sealing is flush with the top surface of the plastic sealing layer, thereby ensuring the welding quality of the inductor 10 and the conductive connection structure 21, and achieving the improvement of the performance and manufacturing yield of the three-dimensional packaging structure.

[0053] In some embodiments, the exhaust groove comprises:

[0054] A first groove 214 is located on the bottom surface of the conductive connection structure 21 facing the substrate 20;

[0055] The second trench 212 is located on a side surface of the conductive connection structure 21 , and the second trench 212 is connected to the first trench 214 .

[0056] In some embodiments, the conductive connection structure 21 has a plurality of first grooves 214 on the bottom surface facing the substrate 20, and each of the first grooves 214 runs through the bottom surface of the conductive connection structure 21 in a direction parallel to the front surface of the substrate 20, and the plurality of first grooves 214 are interconnected, and at least two of the first grooves 214 intersect. The plurality of grooves in this specific embodiment refers to more than two.

[0057] In some embodiments, the conductive connection structure 21 has two perpendicularly intersecting first grooves 214 on the bottom surface facing the substrate 20 , and opposite ends of each first groove 214 are connected to one of the second grooves 212 .

[0058] For example, if Figure 2-Figure 4 As shown, two first grooves 214 are provided on the bottom surface of the conductive connection structure 21 facing the substrate 20, which penetrate the bottom surface of the conductive connection structure 21 in a direction parallel to the front surface of the substrate 20, and the two first grooves 214 intersect vertically to form a cross-shaped structure. The opposite ends of each first groove 214 are respectively connected to a second groove 212, so that the exhaust groove includes a total of four second grooves 212. By providing a plurality of first grooves 214 on the bottom surface of the conductive connection structure 21, and providing a plurality of second grooves 212 respectively connected to the plurality of first grooves 214 at the lower part of the side surface of the conductive connection structure 21, the gas in the solder paste used for welding the conductive connection structure 21 and the substrate 20 can be quickly discharged during the reflow process, and the conductive connection structure 21 can be stably connected to the substrate 20.

[0059] In some embodiments, the second groove 212 is an inverted V-shaped groove, and the width of the bottom surface of the inverted V-shaped groove is the same as the width of the first groove 214, so as to quickly discharge the gas in the solder paste and ensure the stability of the conductive connection structure 21.

[0060] Figure 5 is a schematic diagram of the three-dimensional structure of a part of the substrate in a specific embodiment of the present invention, Figure 6 is a schematic cross-sectional view of a portion of a substrate in a specific embodiment of the present invention, Figure 7Schematic diagram of the relative position relationship between the substrate and the conductive connection structure in a specific embodiment of the present invention. In some embodiments, the front surface of the substrate 20 has a conductive bump 22; the conductive connection structure 21 includes:

[0061] The column body 211 is located on the front surface of the substrate 20, the first groove 214 is located on the bottom surface of the column body 211 facing the substrate 20, and the second groove 212 is located on the side surface of the column body 211;

[0062] The wing portion 213 is protrudingly disposed on the side surface of the column body 211 and is electrically connected to the conductive bump 22 .

[0063] In some embodiments, the material of the column body 211 and the material of the wing portion 213 are both copper.

[0064] In some embodiments, the conductive connection structure 21 and the conductive bump 22 are an integrated structure, and the conductive bump 22 is disposed at the bottom of the wing portion 213 .

[0065] For example, the column body 211 is a copper prism, and the column body 211 extends in a direction perpendicular to the front surface of the substrate 20, such as Figure 5 and Figure 6 As shown. The first groove 214 is located on the bottom surface of the column body 211 facing the substrate 20, the second groove 212 is located at the lower part of the side of the column body 211, and the bottom of the second groove 212 is connected to the end of the first groove 214. The side wing portion 213 is connected to the lower part of the side of the column body 211. The conductive bump 22 is protrudingly arranged on the front side of the substrate 20, the side wing portion 213 is located above the conductive bump 22 in a direction perpendicular to the front side of the substrate 20, and the side wing portion 213 is connected to the conductive bump 22, as shown. Figure 2 and Figure 7 As shown. By providing the wing portion 213 and the conductive bump 22, the stability of the connection between the conductive connection structure 21 and the substrate 20 can be enhanced, and the conductive connection structure 21 can be prevented from shaking during the gas discharge process in the solder paste. In addition, the wing portion 213 is electrically connected to the conductive bump 22, so that the substrate 20 can be electrically connected to the inductor 10 through the column body 211, and can also be electrically connected to the inductor 10 through the wing portion 213 and the column body 211, ensuring the stability and reliability of the electrical connection between the substrate 20 and the inductor 10.

[0066] In some embodiments, the plurality of conductive bumps 22 are symmetrically distributed around the periphery of the column body 211 , the side wing portions 213 are distributed around the side surfaces of the column body 211 , and the side wing portions 213 are in contact with the plurality of conductive bumps 22 toward the bottom surface of the substrate 20 .

[0067] Specifically, the side wing portion 213 is distributed around the side of the column body 211, that is, the side wing portion 213 is annular as a whole, and the multiple conductive bumps 22 are symmetrically distributed around the outer circumference of the column body 211, and all of the conductive bumps 22 are in contact and electrically connected with the side wing portion 213 toward the bottom surface of the substrate 20, so that the supporting force of the multiple conductive bumps 22 on the side wing portion 213 is evenly distributed, and the center of gravity of the column body 211 is lowered, avoiding the conductive connection structure 21 from tilting, thereby further improving the product quality of the three-dimensional packaging structure.

[0068] In some embodiments, Figure 3 and Figure 4 As shown, in the direction perpendicular to the front surface of the substrate 20, the top of the second groove 212 is lower than or flush with the side wing portion 213, so as to simplify the manufacturing process of the conductive connection structure 21. For example, the second groove 212 is an inverted V-shape, and in the direction perpendicular to the front surface of the substrate 20, the top of the second groove 212 is lower than or flush with the side wing portion 213.

[0069] In other embodiments, Figure 2 and Figure 7 As shown, in the direction perpendicular to the front side of the substrate 20, the top of the second groove 212 is higher than the side wing 213. For example, the second groove 212 is an inverted V-shape, and in the direction perpendicular to the front side of the substrate 20, the top of the second groove 212 is higher than the side wing 213. In one example, Figure 7 As shown, the sum of the height a of the second groove 212 (i.e., the distance between the bottom surface of the inverted V-shaped second groove 212 and the vertex of the second groove 212) and the distance d between the bottom surface of the column body 211 and the front surface of the substrate 20 is greater than the distance c between the side wing portion 213 and the front surface of the substrate 20, thereby making it easier to discharge the gas in the solder paste during the reflow process.

[0070] In some embodiments, the three-dimensional packaging structure further includes:

[0071] The solder layer 26 is located at least between the column body 211 and the front surface of the substrate 20. The solder layer 26 includes a plurality of solder beads. The height of the conductive bump 22 is greater than twice the diameter of the solder beads. The distance between the column body 211 and the front surface of the substrate 20 is greater than the diameter of the solder beads.

[0072] For example, if Figure 7 As shown, the solder paste between the conductive connection structure 21 and the substrate 20 forms the solder layer 26 between the column body 211 in the conductive connection structure 21 and the substrate 20 after the reflow process. The height of the conductive bump 22 is equal to the distance c between the side wing portion 213 (e.g., the bottom surface of the side wing portion 213) and the front surface of the substrate 20. The distance between the side wing portion 213 (e.g., the bottom surface of the side wing portion 213) and the front surface of the substrate 20 is c, the distance between the side wing portion 213 (e.g., the bottom surface of the side wing portion 213) and the bottom surface of the column body 211 is b, and the distance between the bottom surface of the column body 211 and the front surface of the substrate 20 is d, and cb=d. The height of the conductive bump 22 is greater than twice the diameter of the solder bead, and the distance d between the bottom surface of the column body 211 and the front surface of the substrate 20 is greater than the diameter of the solder bead, thereby facilitating the stable fixing of the column body 211 on the substrate 20 and further preventing the column body 211 from tilting.

[0073] In one example, the distance e between the conductive bump 22 and the side of the column body 211 is greater than the mounting process accuracy in the horizontal direction (ie, parallel to the front surface of the substrate 20 ), ensuring that the column body 211 can be smoothly mounted on the substrate 20 .

[0074] In some embodiments, the three-dimensional packaging structure further includes:

[0075] The plastic encapsulation layer 12 is located on the front side of the substrate 20 . The plastic encapsulation layer 12 at least encapsulates the chip 24 and the conductive connection structure 21 . The surface of the plastic encapsulation layer 12 facing away from the substrate 20 is flush with the surface of the conductive connection structure 21 facing away from the substrate 20 .

[0076] This specific embodiment also provides a method for forming a three-dimensional packaging structure. Figure 8 is a flow chart of a method for forming a three-dimensional packaging structure in a specific embodiment of the present invention. The schematic diagram of the three-dimensional packaging structure formed in this specific embodiment can be seen in Figure 1-Figure 7 .like Figure 1-Figure 8 As shown, the method for forming the three-dimensional packaging structure includes the following steps:

[0077] Step S81, providing a substrate 20, wherein the substrate 20 includes a front surface and a back surface that are relatively distributed;

[0078] Step S82, mounting the chip 24 on the front surface of the substrate 20;

[0079] Step S83, welding a conductive connection structure 21 on the front surface of the substrate 20, wherein the bottom end of the conductive connection structure 21 is electrically connected to the substrate 20, and the bottom end of the conductive connection structure 21 has an exhaust groove, and the exhaust groove at least extends to the edge of the conductive connection structure 21;

[0080] Step S84, mounting the inductor 10 on the side of the chip 24 away from the substrate 20, and forming a plastic encapsulation layer 12 on the front side of the substrate 20 to at least encapsulate the chip 24 and the conductive connection structure 21, the inductor 10 is electrically connected to the top of the conductive connection structure 21, and the surface of the plastic encapsulation layer 12 away from the substrate 20 is flush with the surface of the conductive connection structure 21 away from the substrate 20.

[0081] In some embodiments, the specific steps of welding the conductive connection structure 21 on the front surface of the substrate 20 include:

[0082] A conductive connection structure 21 having an exhaust groove at the bottom is formed, wherein the exhaust groove includes a first groove 214 located on the bottom surface of the conductive connection structure 21 facing the substrate 20 and a second groove 212 located on the side surface of the conductive connection structure 21, and the second groove 212 is connected to the first groove 214;

[0083] The conductive connection structure 21 is soldered to the front side of the substrate 20 via a solder layer 26 .

[0084] In some embodiments, the substrate 20 has a conductive bump 22 on the front surface; the specific steps of forming a conductive connection structure 21 having an exhaust groove at the bottom include:

[0085] A column body 211 having an exhaust groove at the bottom and a side wing portion 213 protruding from the side of the column body 211 are formed, the first groove 214 is located on the bottom surface of the column body 211 facing the substrate 20, the second groove 212 is located on the side of the column body 211, and the side wing portion 213 is used to be electrically connected to the conductive bump 22.

[0086] The three-dimensional packaging structure and the formation method thereof provided in this specific embodiment electrically connect the substrate and the inductor through a conductive connection structure, and the bottom end of the conductive connection structure has an exhaust groove, and the exhaust groove extends at least to the edge of the conductive connection structure, so that the gas in the solder paste used for welding the conductive connection structure and the substrate can be discharged through the exhaust groove during the reflow soldering process, reducing or even avoiding the generation of voids between the conductive connection structure and the substrate, thereby avoiding the gas in the void from expanding due to heat during the subsequent plastic sealing process and pushing the conductive connection structure to move upward, eliminating the coplanarity problem between the conductive connection structure and the plastic sealing layer, that is, making the top surface of the conductive connection structure flush with the top surface of the plastic sealing layer after plastic sealing, thereby ensuring the welding quality of the inductor and the conductive connection structure, and achieving the improvement of the performance and manufacturing yield of the three-dimensional packaging structure. In addition, this specific embodiment improves the stability of the connection between the conductive connection structure and the substrate, reduces or even avoids the tilting of the conductive connection structure, and achieves further improvement in the performance and manufacturing yield of the three-dimensional packaging structure by configuring the conductive connection structure to include a column body and a side wing portion protruding on the side of the column body, and electrically connecting the side wing portion to the conductive bump on the substrate.

[0087] The above 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 principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A three-dimensional packaging structure, characterized in that: include: A substrate, the substrate comprising a front surface and a back surface that are oppositely distributed; A chip is mounted on the front side of the substrate; an inductor, located at a side of the chip facing away from the substrate; A conductive connection structure is located on the front side of the substrate, and the bottom end of the conductive connection structure is electrically connected to the substrate, and the top end is electrically connected to the inductor. The bottom end of the conductive connection structure has an exhaust groove, and the exhaust groove extends at least to the edge of the conductive connection structure.

2. The three-dimensional packaging structure according to claim 1, characterized in that: The exhaust groove comprises: A first groove is located on the bottom surface of the conductive connection structure facing the substrate; The second trench is located on a side surface of the conductive connection structure, and the second trench is connected to the first trench.

3. The three-dimensional packaging structure according to claim 2, characterized in that: The conductive connection structure has a plurality of first grooves on the bottom surface facing the substrate, and each of the first grooves penetrates the bottom surface of the conductive connection structure in a direction parallel to the front surface of the substrate, the plurality of first grooves are interconnected, and at least two of the first grooves intersect.

4. The three-dimensional packaging structure according to claim 3, characterized in that: The conductive connection structure has two first grooves that intersect vertically on the bottom surface facing the substrate, and opposite ends of each first groove are connected to one of the second grooves respectively.

5. The three-dimensional packaging structure according to claim 2, characterized in that: The second groove is an inverted V-shaped groove, and the width of the bottom surface of the inverted V-shaped groove is the same as the width of the first groove.

6. The three-dimensional packaging structure according to claim 2, characterized in that: The front surface of the substrate has a conductive bump; the conductive connection structure includes: A column body is located on the front surface of the substrate, the first groove is located on the bottom surface of the column body facing the substrate, and the second groove is located on the side surface of the column body; The wing portion is protrudingly disposed on the side surface of the column body and is electrically connected to the conductive bump.

7. The three-dimensional packaging structure according to claim 6, characterized in that: The plurality of conductive bumps are symmetrically distributed around the periphery of the column body, the wing portions are distributed around the side surfaces of the column body, and the wing portions are in contact with and connected to the plurality of conductive bumps toward the bottom surface of the substrate.

8. The three-dimensional packaging structure according to claim 6, characterized in that: In a direction perpendicular to the front surface of the substrate, a top end of the second groove is higher than the side wing portion.

9. The three-dimensional packaging structure according to claim 6, characterized in that: Also includes: The solder layer is located at least between the column body and the front surface of the substrate. The solder layer includes a plurality of solder beads. The height of the conductive bump is greater than twice the diameter of the solder beads. The distance between the column body and the front surface of the substrate is greater than the diameter of the solder beads.

10. The three-dimensional packaging structure according to claim 6, characterized in that: The material of the column body and the material of the wing portion are both copper.

11. The three-dimensional packaging structure according to claim 1, characterized in that: Also includes: The plastic encapsulation layer is located on the front side of the substrate. The plastic encapsulation layer at least encapsulates the chip and the conductive connection structure. The surface of the plastic encapsulation layer facing away from the substrate is flush with the surface of the conductive connection structure facing away from the substrate.

12. A method for forming a three-dimensional packaging structure, characterized in that: The steps include: Providing a substrate, the substrate comprising a front surface and a back surface that are oppositely distributed; Mounting a chip on the front side of the substrate; Welding a conductive connection structure on the front side of the substrate, wherein the bottom end of the conductive connection structure is electrically connected to the substrate, the bottom end of the conductive connection structure has an exhaust groove, and the exhaust groove at least extends to the edge of the conductive connection structure; The inductor is mounted on the side of the chip facing away from the substrate, and a plastic sealing layer is formed on the front side of the substrate to at least seal the chip and the conductive connection structure. The inductor is electrically connected to the top of the conductive connection structure, and the surface of the plastic sealing layer facing away from the substrate is flush with the surface of the conductive connection structure facing away from the substrate.

13. The method for forming a three-dimensional packaging structure according to claim 12, characterized in that: The specific steps of welding the conductive connection structure on the front side of the substrate include: forming a conductive connection structure having an exhaust groove at the bottom end, wherein the exhaust groove comprises a first groove located on the bottom surface of the conductive connection structure facing the substrate and a second groove located on the side surface of the conductive connection structure, and the second groove is connected to the first groove; The conductive connection structure is soldered to the front side of the substrate through a solder layer.

14. The method for forming a three-dimensional packaging structure according to claim 13, characterized in that: The substrate has a conductive bump on the front side; the specific steps of forming a conductive connection structure with an exhaust groove at the bottom include: A column body having an exhaust groove at the bottom and a wing portion protruding from the side of the column body are formed, wherein the first groove is located on the bottom surface of the column body facing the substrate, the second groove is located on the side of the column body, and the wing portion is used to be electrically connected to the conductive bump.

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