Groove type packaging structure

Abstract

The utility model discloses a groove type packaging structure, and relates to the technical field of packaging, the groove type packaging structure comprises a chip and a substrate, the chip is provided with a first welding pad, the substrate is provided with a second welding pad, and the first welding pad and the second welding pad are connected through welding balls in a welding mode. And a groove structure for bonding the solder ball is formed on the welding surface of the first welding pad and / or the welding surface of the second welding pad. Wherein the groove bottom of the groove structure extends into the metal layer of the first welding pad and / or the metal layer of the second welding pad, and at least one groove structure is arranged between the central area of the first welding pad or the second welding pad and the edge area of the first welding pad or the second welding pad. The groove structure is arranged on the welding surface of the first welding pad and / or the welding surface of the second welding pad, so that the connecting surface area of the welding ball and the first welding pad and / or the second welding pad is increased, the connecting strength and reliability between the welding ball and the first welding pad and / or the second welding pad are further improved, a stress buffering effect can be provided, and diffusion of potential microcracks is prevented.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of packaging technology, in particular to a groove type packaging structure. BACKGROUND

[0002] Flip Chip (FC) is a chip mounting technology used in microelectronic packaging, the front side of the chip (i.e. the side with the circuit) is turned over to face the packaging substrate, then the bumps on the chip are aligned with the corresponding pads on the packaging substrate and soldered together. This chip mounting technology can significantly reduce the packaging size and signal transmission path length, thus improving performance and reducing power consumption.

[0003] To complete the flip chip, it is usually necessary to make cylindrical metal pads on the chip, such as pure copper metal pads, or metal pads with a copper / nickel layer structure, or even a copper / nickel / gold layer structure, and then continue to make spherical tin-based alloy bumps, also known as solder balls, such as tin-silver balls, tin-silver-copper balls, on the pads, and then through a one-time reflow soldering, the interface between the solder balls and the pads will form intermetallic compounds (IMC), such as Cu6Sn5, Cu3Sn, Ni6Sn5, Ni3Sn, etc., which will effectively bond the solder balls and the pads; on the packaging substrate, cylindrical metal pads, such as pure copper metal pads, or metal pads with a copper / nickel / gold layer structure, or even a copper / nickel / gold layer structure, are also needed, when the chip is facing the packaging substrate and the bumps on the chip are aligned with the corresponding pads on the packaging substrate, through a one-time reflow soldering, the interface between the pads on the chip side and the solder balls will continue to form more IMC based on the previously formed IMC, while the interface between the pads on the packaging substrate side and the solder balls will form IMC, such as Cu6Sn5, Cu3Sn, Ni6Sn5, Ni3Sn, etc., which will effectively bond the solder balls and the pads; finally, the chip and the packaging substrate are effectively bonded.

[0004] The life and reliability of the solder joint are related to the IMC at the interface between the solder balls and the pads, at present, the common failure modes are the interface fracture between the solder balls and the pads on the chip side, and the interface fracture between the solder balls and the pads on the substrate side, while the solder ball itself fracture or the pad itself fracture is rarely seen. Therefore, it is urgent to improve the interface structure of the pads and the solder balls to enhance the reliability of the solder joint. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a groove type packaging structure to solve the problem of low reliability of the interface solder joint between the pads and the solder balls in the prior art.

[0006] The above-mentioned purpose of the utility model can be realized by adopting the following technical scheme:

[0007] The utility model provides a kind of trench type packaging structure, including chip and substrate, the first solder pad is provided on the chip, the second solder pad is provided on the substrate, the first solder pad and the second solder pad are connected by solder ball welding, and the groove structure for the solder ball bonding is formed on the welding surface of the first solder pad and / or the welding surface of the second solder pad.

[0008] Specifically, the groove bottom of the groove structure extends into the metal layer of the first solder pad and / or the metal layer of the second solder pad, and at least one groove structure is provided between the central region of the first solder pad or the second solder pad and the edge region thereof.

[0009] Specifically, in the state that the chip and the substrate are in the packaging state, the surface bonded by the solder ball and the groove structure is formed with an intermetallic compound layer.

[0010] Preferably, the cross section of the groove structure is in the shape of a truncated cone or a rectangle.

[0011] Preferably, the groove structure on the first solder pad is an annular groove.

[0012] Preferably, the annular groove is a plurality, and the plurality of annular grooves are arranged at intervals from the central region to the edge region of the first solder pad, and a first metal ring is formed between the two adjacent annular grooves.

[0013] Preferably, from the central region to the edge region of the first solder pad, the groove width of the plurality of annular grooves increases in turn.

[0014] Preferably, the groove structure on the second solder pad includes at least one groove ring formed by a plurality of circumferentially spaced arc-shaped grooves, and a metal layer conduction structure is formed between the two adjacent arc-shaped grooves in the groove ring.

[0015] Preferably, in the state that the second solder pad is electrically interconnected with the same layer corresponding electrical network through the metal hole directly below the central region thereof, the outer diameter of the central region of the second solder pad is greater than the diameter of the metal hole.

[0016] Preferably, the groove ring is a plurality, and the plurality of groove rings are arranged at intervals from the central region to the edge region of the second solder pad, a second metal ring is formed between the two adjacent groove rings, and the plurality of metal layer conduction structures between the two adjacent second metal rings are conduction.

[0017] Preferably, the plurality of metal layer conduction structures arranged in the same circumference with the groove ring form a metal layer conduction part, and the plurality of metal layer conduction structures of the two adjacent metal layer conduction parts are arranged staggered along the circumferential direction of the second solder pad.

[0018] Preferably, along the circumferential direction of the second solder pad, a plurality of metal layer conductive structures of the metal layer conductive portion are evenly distributed, and the plurality of metal layer conductive structures of one metal layer conductive portion are located on the angle bisector of the angle formed by two adjacent metal layer conductive structures of another metal layer conductive portion.

[0019] Preferably, the metal layer conductive portion includes four metal layer conductive structures, and the corresponding misalignment angle between the metal layer conductive structures of one of two adjacent metal layer conductive portions and the metal layer conductive structures of the other is 45°.

[0020] The features and advantages of this utility model are as follows: The trench packaging structure provided by this utility model can increase the connection surface area between the solder ball and the first solder pad and / or the second solder pad without increasing the packaging process steps by setting a trench structure on the soldering surface of the first solder pad on the chip and / or the soldering surface of the second solder pad on the substrate, thereby improving the connection strength and reliability between the two, and providing stress buffering effect to prevent the propagation of potential microcracks. Attached Figure Description

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

[0022] Figure 1 This is a cross-sectional schematic diagram of a first solder pad with an annular groove provided in an embodiment of the present invention;

[0023] Figure 2 This is a top view of a first solder pad with an annular groove provided in an embodiment of the present invention;

[0024] Figure 3 This is a cross-sectional schematic diagram of the bonding between the first solder pad and the solder ball provided in an embodiment of this utility model;

[0025] Figure 4 This is a cross-sectional schematic diagram of a first bonding pad with multiple annular grooves provided in an embodiment of the present invention;

[0026] Figure 5 This is a top view of the first bonding pad with multiple annular grooves provided in an embodiment of the present invention;

[0027] Figure 6This is a cross-sectional view of the second solder pad with a grooved ring provided in the embodiment of the present invention, showing the solder pad leading out a trace.

[0028] Figure 7 This is a top view of the second solder pad with a grooved ring provided in the embodiment of the present invention, showing the solder pad leading out a trace.

[0029] Figure 8 This is a cross-sectional view of the second solder pad with a grooved ring being led out through a metal hole in an embodiment of the present invention.

[0030] Figure 9 This is a top view of the second solder pad with a grooved ring provided in this embodiment of the present invention, showing the trace being led out through a metal hole.

[0031] Figure 10 This is a cross-sectional schematic diagram of the bonding between the second solder pad and the solder ball provided in an embodiment of this utility model;

[0032] Figure 11 This is a top view of the second solder pad with multiple grooved rings in the embodiment of the present invention, showing the solder pad lead-out trace.

[0033] Figure 12 This is a top view of the second solder pad with multiple grooved rings in the embodiment of the present invention, showing the trace being led out through a metal hole.

[0034] Explanation of icon numbers:

[0035] 1. First solder pad; 11. Aluminum solder pad; 12. Passivation layer; 13. First dielectric layer; 14. Second dielectric layer; 15. First sputtering layer; 16. First circuit layer; 17. Second sputtering layer; 18. First metal layer;

[0036] 2. Second solder pad; 21. Substrate layer; 22. Solder resist layer; 23. Second metal layer; 24. Metal via;

[0037] 3. Welding balls;

[0038] 4. Annular groove;

[0039] 5. First metal ring;

[0040] 6. Arc-shaped groove;

[0041] 7. Conductive structure of metal layer;

[0042] 8. Second metal ring;

[0043] 9. Intermetallic compound layer. Detailed Implementation

[0044] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0045] like Figures 1 to 12 As shown, this utility model provides a trench packaging structure, including a chip and a substrate. A first bonding pad 1 is disposed on the chip, and a second bonding pad 2 is disposed on the substrate. The first bonding pad 1 and the second bonding pad 2 are connected by solder balls 3. A trench structure for bonding the solder balls 3 is formed on the soldering surface of the first bonding pad 1 and / or the soldering surface of the second bonding pad 2. By forming a trench structure on the soldering surface of the first bonding pad 1 and / or the soldering surface of the second bonding pad 2, the connection surface area between the solder balls 3 and the first bonding pad 1 and / or the second bonding pad 2 is increased, thereby improving the connection strength and reliability between them.

[0046] For example, such as Figures 1 to 12 As shown, the first pad 1 (chip-side pad) and the second pad 2 (substrate-side pad) are both circular pads. The first pad 1 includes an aluminum pad 11, a passivation layer 12, a first dielectric layer 13 and a second dielectric layer 14 arranged sequentially toward the solder ball 3. The central area of ​​the second dielectric layer 14 is provided with a first sputtering layer 15, a first circuit layer 16, a second sputtering layer 17 and a first metal layer 18 stacked sequentially toward the solder ball 3. The second pad 2 includes a substrate layer 21 and a solder resist layer 22 arranged sequentially toward the solder ball 3. The central area of ​​the solder resist layer 22 forms a second metal layer 23. The surface of the first metal layer 18 is the welding surface of the first pad 1, and the surface of the second metal layer 23 is the welding surface of the second pad 2.

[0047] When a groove structure for bonding solder balls 3 is formed on the welding surface of the first solder pad 1, the welding process between the solder balls 3 and the first solder pad 1 includes: applying flux to the welding surface of the first solder pad 1; placing the pre-formed solder balls 3 onto the welding surface of the first solder pad 1, whereby the solder balls 3 adhere to the first solder pad 1 under the action of the flux, preventing them from moving; and reflow soldering, which involves subjecting the wafer to a high temperature (the peak temperature must be greater than the eutectic point of the alloy material contained in the solder balls 3). The molten alloy of the solder balls 3 wets the welding surface of the first solder pad 1, and an intermetallic compound (IMC) is formed on the welding surface of the solder balls 3 and the first solder pad 1. Under the action of liquid surface tension, the solder balls 3 maintain their spherical shape, while the flux evaporates and disappears. The intermetallic compound cools to form an intermetallic compound layer 9 on the bonding surface of the solder balls 3 and the first solder pad 1, thus forming a reliable bond between the solder balls 3 and the first solder pad 1. It should be noted that, as Figure 3As shown, the intermetallic compound layer 9 is formed on the top surface of the first solder pad 1 and on the bottom and sidewalls of the trench structure. Compared with the prior art, the surface area and total amount of the intermetallic compound are significantly improved. In addition, the trench structure can provide stress buffering effect, prevent the propagation of potential microcracks, and make the welding surface between the solder ball 3 and the first solder pad 1 less prone to breakage, thereby improving the connection strength and reliability between the two.

[0048] When a groove structure for bonding solder balls 3 is formed on the welding surface of the second solder pad 2, the welding process between the solder balls 3 and the second solder pad 2 includes: applying flux to the welding surface of the second solder pad 2; aligning the chip with the substrate and aligning the solder balls 3 (bumps) connected to the chip with the corresponding second solder pads 2 on the substrate; reflow soldering, where the molten solder ball 3 alloy wets the welding surface of the second solder pad 2, and an intermetallic compound forms on the welding surface of the solder balls 3 and the second solder pad 2. Under the action of liquid surface tension, the solder balls 3 maintain their spherical shape, while the flux evaporates and disappears. The intermetallic compound cools to form an intermetallic compound layer 9 on the bonding surface of the solder balls 3 and the second solder pad 2, thus forming a reliable bond between the solder balls 3 and the second solder pad 2. It should be noted that, as Figure 10 As shown, the intermetallic compound layer 9 is formed on the top surface of the second solder pad 2 and the sidewalls of the trench structure. Compared with the prior art, although the surface area and total amount of the intermetallic compound have not been significantly improved, the trench structure can provide stress buffering effect, prevent the propagation of potential microcracks, and make the welding surface between the solder ball 3 and the second solder pad 2 less prone to breakage, thereby improving the connection strength and reliability between the two.

[0049] According to one embodiment of the present invention, the bottom of the trench structure extends into the metal layer of the first solder pad 1 and / or the metal layer of the second solder pad 2, and at least one trench structure is provided between the central area and the edge area of ​​the first solder pad 1 or the second solder pad 2. In this embodiment, as... Figure 1 , Figures 3 to 4 , Figure 6 , Figure 8 and Figure 10 As shown, the trench structure on the first pad 1 extends from the surface of the first metal layer 18 to the first sputtered layer 15, and the trench structure on the second pad 2 extends from the surface of the second metal layer 23 to the substrate layer 21, to increase the surface area and total amount of intermetallic compounds. Wherein, as... Figure 2 , Figure 5 , Figure 7 , Figure 9 and Figures 11 to 12As shown, to avoid stress imbalance leading to localized solder joint cracking, the center of the trench structure is concentrically positioned with the center of the welding surface. Furthermore, to ensure compatibility with this application, the trench structure is positioned between the central region and the edge region of the welding surface. That is, the central and edge regions of the welding surface retain the conventional metal layer structure without the trench structure. This accommodates the conventional design where chip-side pads / or substrate-side pads still use a flat metal layer as the welding surface during chip packaging. Simultaneously, the metal layer structure in the central region of the welding surface maintains stress balance with the conventionally designed central region, which helps improve the reliability of the solder joint. In this embodiment, based on existing process technology, the diameter of the central region of the welding surface on the chip-side pad is not less than 20 μm, and the diameter of the central region of the welding surface on the substrate-side pad is not less than 50 μm.

[0050] Specifically, when the chip and substrate are in a packaged state, an intermetallic compound layer 9 is formed on the surface where the solder ball 3 is bonded to the trench structure. In some embodiments, such as Figure 3 As shown, for the chip-side solder pads, the surface where the solder ball 3 bonds to the trench structure includes the trench bottom and sidewalls; as Figure 10 As shown, for the substrate-side solder pads, the surface where the solder ball 3 bonds to the trench structure only includes the sidewall of the trench structure.

[0051] According to a preferred embodiment of the present invention, the cross-section of the trench structure is frustoconical or rectangular. For example, along the radial direction of the solder pad, the cross-section of the trench structure is frustoconical or rectangular to facilitate fabrication and to accommodate the surface area of ​​the bonding ball 3 to the trench structure. The chip-side solder pads are generally fabricated using a semi-additive method. First, an electroplated substrate film is deposited on the front side to make the entire substrate conductive. Then, photolithography is used to cover the areas that do not require electroplating with photoresist. Subsequently, the desired metal pattern is electroplated, and finally, the photoresist and electroplated substrate film are removed. Therefore, chip-side solder pads can be fabricated into island-like copper sheets, and thus, chip-side solder pads can employ complete annular trenches. Substrate-side solder pads are generally fabricated using an etching method. First, a metal pattern is etched onto the substrate surface. After etching, a nickel wetting layer and a gold anti-oxidation layer are electroplated onto the surface of the metal pattern. If the substrate-side solder pad has isolated copper islands, the wetting layer and anti-oxidation layer cannot be electroplated. Therefore, limited by the nickel-gold electroplating surface treatment process, the substrate-side solder pad can only use incomplete annular grooves, that is, multiple arc-shaped grooves 6 spaced apart along the circumference of the substrate-side solder pad to ensure electrical connection between the inner and outer metals. Furthermore, to ensure stress balance, the multiple arc-shaped grooves 6 on the same circumference of the substrate-side solder pad are evenly distributed.

[0052] According to a preferred embodiment of the present invention, such as Figure 2 and Figure 5 As shown, the groove structure on the first pad 1 is an annular groove 4 to obtain a larger surface area for bonding between the solder ball 3 and the groove structure.

[0053] According to a preferred embodiment of the present invention, such as Figure 5 As shown, there are multiple annular grooves 4, which are spaced apart from the center area of ​​the first pad 1 towards its edge area, and a first metal ring 5 is formed between two adjacent annular grooves 4. In this way, the surface area of ​​the bonding between the solder ball 3 and the groove structure and the support strength of the chip-side pad for the solder ball 3 are taken into account, so that the connection between the solder ball 3 and the chip-side pad has a better stress buffering effect.

[0054] According to a preferred embodiment of the present invention, such as Figure 4 and Figure 5 As shown, from the center area of ​​the first pad 1 to its edge area, the width of the multiple annular grooves 4 increases sequentially to further strengthen the bonding strength between the solder ball 3 and the edge of the chip-side pad, and to avoid the connection interface between the solder ball 3 and the chip-side pad breaking due to edge bonding failure.

[0055] According to a preferred embodiment of the present invention, such as Figure 7 , Figure 9 and Figures 11 to 12 As shown, the trench structure on the second pad 2 includes at least one trench ring formed by a plurality of circumferentially spaced arcuate grooves 6, and a metal layer conductive structure 7 is formed between two adjacent arcuate grooves 6 within the trench ring. By configuring the trench structure as a trench ring formed by a plurality of spaced arcuate grooves 6, the trench structure is suitable for the etching process of the substrate-side pads.

[0056] According to a preferred embodiment of the present invention, when the second solder pad 2 is electrically interconnected with the corresponding electrical network of the same layer through the metal hole 24 directly below its central region, the outer diameter of the central region of the second solder pad 2 is larger than the diameter of the metal hole 24. For example, as... Figure 7 , Figure 9 and Figures 11 to 12 As shown, when the diameter of the second metal layer 23 of the second pad 2 is smaller than the opening diameter of the solder resist layer 22, traces can be directly led out through the second pad 2 or through the metal hole 24 directly below the center area of ​​the second pad 2 to achieve electrical interconnection with the corresponding electrical network on the same layer. When the trace is led out through the metal hole 24, setting the outer diameter of the center area of ​​the substrate-side pad to be larger than the diameter of the metal hole 24 can prevent the metal hole 24 from directly contacting the solder, ensuring that the solder only contacts the second metal layer 23 of the substrate-side pad, thereby ensuring the reliability requirements of the soldering process.

[0057] A preferred embodiment of this utility model is as follows: Figures 11 to 12As shown, there are multiple trench rings, spaced apart from the center region of the second pad 2 towards its edge region. A second metal ring 8 is formed between two adjacent trench rings, and two adjacent second metal rings 8 are connected by multiple metal layer conductive structures 7. In this way, the surface area for bonding between the solder ball 3 and the trench structure and the support strength of the substrate-side solder pad for the solder ball 3 are considered, so that the connection between the solder ball 3 and the substrate-side solder pad has a better stress buffering effect.

[0058] Preferably, from the center area of ​​the second pad 2 towards its edge area, the width of the arc-shaped groove 6 in the multiple groove rings increases sequentially to further strengthen the bonding strength between the solder ball 3 and the edge of the substrate-side pad, and to avoid the connection interface between the solder ball 3 and the substrate-side pad breaking due to edge bonding failure.

[0059] According to a preferred embodiment of the present invention, a plurality of metal layer conductive structures 7 arranged on the same circumference as the groove ring form a metal layer conductive portion. The plurality of metal layer conductive structures 7 of two adjacent metal layer conductive portions are staggered along the circumferential direction of the second solder pad 2 to prevent stress concentration, thereby improving the reliability of the solder ball 3 and the substrate side solder pad.

[0060] According to a preferred embodiment of the present invention, multiple metal layer conductive structures 7 of the metal layer conductive portion are evenly distributed along the circumferential direction of the second solder pad 2. That is, multiple arc-shaped grooves 6 of the groove ring are equally spaced along the circumferential direction of the second solder pad 2. Multiple metal layer conductive structures 7 of one metal layer conductive portion are located on the angle bisector of the angle formed by two adjacent metal layer conductive structures 7 of another metal layer conductive portion, so as to obtain a better stress balance effect.

[0061] According to a preferred embodiment of the present invention, the metal layer conductive portion includes four metal layer conductive structures 7, and the corresponding misalignment angle between the metal layer conductive structures 7 of one of two adjacent metal layer conductive portions and the metal layer conductive structures 7 of the other is 45°. For example, as... Figures 11 to 12 As shown, the four metal layer conductive structures 7 of the metal layer conductive part are evenly distributed to form a hollow cross shape. The included angle between two adjacent metal layer conductive structures 7 is 90°. In order to obtain a better stress balance effect, the multiple metal layer conductive structures 7 of one of the two adjacent metal layer conductive parts are located on the angle bisector of the included angle between the two adjacent metal layer conductive structures 7 of the other. That is, after one of the two adjacent metal layer conductive parts is rotated 45° clockwise or counterclockwise, each metal layer conductive structure 7 in that metal layer conductive part can be aligned with each metal layer conductive structure 7 in the other metal layer conductive part.

[0062] Based on the above description, the trench-type packaging structure provided in the embodiments of this utility model has the following beneficial effects:

[0063] The trench packaging structure provided in this embodiment of the present invention increases the connection surface area between the solder ball 3 and the first solder pad 1 and / or the second solder pad 2 without increasing the packaging process steps by setting trench structures on the soldering surface of the first solder pad 1 and / or the second solder pad 2 on the soldering surface of the first solder pad 1 and / or the second solder pad 2. This improves the connection strength and reliability between the two and provides a stress buffering effect, preventing the propagation of potential microcracks. By setting the trench structure between the central area and the edge area of ​​the soldering surface, it also takes into account the applicability of the conventional design where the chip-side solder pads and / or the substrate-side solder pads still use a metal layer plane as the soldering surface during chip packaging. When the metal layer structure in the center area of ​​the welding surface can maintain stress balance with the conventionally designed center area, it is beneficial to improve the reliability of the solder joint. Furthermore, by setting the groove structure on the substrate-side solder pad as a groove ring formed by multiple spaced arc grooves 6, the groove structure is suitable for the etching process of the substrate-side solder pad. In addition, by setting multiple arc grooves 6 of the groove ring at equal intervals along the circumference of the substrate-side solder pad, and by placing multiple metal layer conductive structures 7 of one of the adjacent metal layer conductive parts on the bisector of the angle formed by the two adjacent metal layer conductive structures 7 of the other metal layer conductive part, a better stress balance effect is obtained.

[0064] The above descriptions are merely a few embodiments of this utility model. Those skilled in the art can make various modifications or variations to the embodiments of this utility model based on the content disclosed in the application documents without departing from the spirit and scope of this utility model.

Claims

1. A trench packaging structure, comprising a chip and a substrate, wherein a first bonding pad is disposed on the chip, and a second bonding pad is disposed on the substrate, characterized in that, The first solder pad and the second solder pad are connected by solder ball welding, and a groove structure for solder ball bonding is formed on the welding surface of the first solder pad and / or the welding surface of the second solder pad.

2. The trench packaging structure according to claim 1, characterized in that, The bottom of the trench structure extends into the metal layer of the first solder pad and / or the metal layer of the second solder pad, and at least one of the trench structures is provided between the central area and the edge area of ​​the first solder pad or the second solder pad.

3. The trench packaging structure according to claim 2, characterized in that, The cross-section of the trench structure is frustoconical or rectangular.

4. The trench-type packaging structure according to claim 2, characterized in that, The groove structure on the first solder pad is an annular groove.

5. The trench-type packaging structure according to claim 4, characterized in that, There are multiple annular grooves, which are spaced apart from the center area of ​​the first pad towards its edge area, and a first metal ring is formed between two adjacent annular grooves.

6. The trench packaging structure according to claim 5, characterized in that, The width of the plurality of annular grooves increases sequentially from the center region of the first solder pad toward its edge region.

7. The trench-type packaging structure according to claim 2, characterized in that, The groove structure on the second pad includes at least one groove ring formed by multiple circumferentially spaced arc grooves, and a metal layer conductive structure is formed between two adjacent arc grooves in the groove ring.

8. The trench packaging structure according to claim 7, characterized in that, When the second pad is electrically interconnected with the corresponding electrical network in the same layer through a metal hole directly below its central area, the outer diameter of the central area of ​​the second pad is larger than the diameter of the metal hole.

9. The trench packaging structure according to claim 7 or 8, characterized in that, There are multiple groove rings, which are spaced apart from the center area of ​​the second pad towards its edge area. A second metal ring is formed between two adjacent groove rings, and two adjacent second metal rings are connected by multiple metal layer conductive structures.

10. The trench-type packaging structure according to claim 9, characterized in that, Multiple metal layer conductive structures arranged circumferentially with the groove ring form a metal layer conductive portion, and multiple metal layer conductive structures of two adjacent metal layer conductive portions are staggered along the circumferential direction of the second pad.

11. The trench packaging structure according to claim 10, characterized in that, Along the circumferential direction of the second solder pad, a plurality of metal layer conductive structures of the metal layer conductive portion are evenly distributed, and the plurality of metal layer conductive structures of one metal layer conductive portion are located on the angle bisector of the angle formed by two adjacent metal layer conductive structures of another metal layer conductive portion.

12. The trench packaging structure according to claim 1, characterized in that, When the chip and the substrate are in a packaged state, an intermetallic compound layer is formed on the surface where the solder balls are bonded to the trench structure.

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