CN219738952U

CN219738952U - Chip packaging structure

Info

Publication number: CN219738952U
Application number: CN202321229547.XU
Authority: CN
Inventors: 柳初发
Original assignee: SHENZHEN CULTRAVIEW DIGITAL TECHNOLOGY CO LTD
Current assignee: SHENZHEN CULTRAVIEW DIGITAL TECHNOLOGY CO LTD
Priority date: 2023-05-19
Filing date: 2023-05-19
Publication date: 2023-09-22
Anticipated expiration: 2033-05-19

Abstract

The utility model is applicable to the technical field of electronic devices, and provides a chip packaging structure which comprises a substrate, wherein the substrate is provided with a welding surface, the welding surface comprises an inner welding area and a peripheral welding area, the peripheral welding area is arranged on the periphery of the inner welding area in a surrounding mode, a plurality of bonding pads are distributed at intervals in the inner welding area and the peripheral welding area, the bonding pad positioned in the inner welding area is a first bonding pad, and the bonding pad positioned in the peripheral welding area is a second bonding pad. The distance between two nearest first bonding pads is a first distance, the distance between at least two adjacent second bonding pads is a second distance, and the distance between at least one second bonding pad and the adjacent first bonding pad is a third distance. The second distance is greater than the first distance and/or the third distance is greater than the first distance. The arrangement is such that the distance between at least one second bonding pad in the peripheral bonding pad and an adjacent bonding pad is greater, thereby reducing to some extent the occurrence of short circuits between the bonding pad of the peripheral bonding pad and its adjacent bonding pad.

Description

Chip packaging structure

Technical Field

The utility model relates to the technical field of electronic devices, in particular to a chip packaging structure.

Background

The BGA package (Ball Grid Array Package), also called a ball grid array package, can accommodate more pins, and is one of the most popular chip packaging modes at present because of its advantages of better electrothermal performance, smaller volume, and smaller signal transmission delay.

The entire bottom surface of a BGA package may be used as a pin, and a plurality of solder balls are typically distributed on the bottom surface of a conventional BGA package, and may be used as pins. However, as the precision of the electronic chip is higher, the density of solder balls distributed on the bottom surface of the BGA package is higher, and the space between adjacent solder balls is smaller, so that a short circuit condition often occurs between the solder balls located in the peripheral area and the adjacent solder balls in the BGA package.

Disclosure of Invention

The embodiment of the utility model aims to provide a chip packaging structure, which aims to solve the technical problem that short circuit situations often occur between solder balls positioned in a peripheral area and adjacent solder balls in BGA packaging in the prior art.

In order to achieve the above purpose, the utility model adopts the following technical scheme: the chip packaging structure comprises a substrate, wherein the substrate is provided with a welding surface, the welding surface comprises an inner welding area and a peripheral welding area, the peripheral welding area is arranged on the periphery of the inner welding area in a surrounding mode, a plurality of bonding pads are distributed at intervals in the inner welding area and the peripheral welding area, the bonding pads located in the inner welding area are first bonding pads, and the bonding pads located in the peripheral welding area are second bonding pads;

the distance between the two nearest first bonding pads is a first distance, the distance between at least two adjacent second bonding pads is a second distance, and the distance between at least one second bonding pad and the adjacent first bonding pads is a third distance;

the second distance is greater than the first distance and/or the third distance is greater than the first distance.

In one possible design, the bonding surface is polygonal, the second bonding pad located at each corner on the bonding surface is a corner bonding pad, the second bonding pad located between two adjacent corner bonding pads is a middle bonding pad, and a distance between the corner bonding pad and the adjacent middle bonding pad is a second distance, wherein the second distance is greater than the first distance.

In one possible design, the distance between at least one of the mid-section pads and the adjacent first pad is a third distance, the third distance being greater than the first distance.

In one possible design, a plurality of middle-section pads are spaced between every two corner pads, among the plurality of middle-section pads, the middle-section pad close to the corner pad is an end pad, and a distance between the end pad and the adjacent first pad is a third distance.

In one possible design, the bonding pad is spherical, the bonding pad has a diameter D, the second distance is less than D/2 from the first distance, and/or the third distance is less than D/2 from the first distance.

In one possible design, the second distance differs from the first distance by D/4, and/or the third distance differs from the first distance by D/4.

In one possible design, at least one of the second pads is ellipsoidal, the first pad is spherical, and the diameter of the spherical pad is equal to the length of the major axis of the ellipsoidal pad.

In one possible design, the distance between at least one ellipsoidal second pad and the adjacent second pad is a second distance, and the distance between at least one ellipsoidal second pad and the adjacent first pad is a third distance.

In one possible design, at least one of the second pads is in the shape of a droplet, the first pad and the second pad are in the shape of a sphere, the length of the droplet is equal to the diameter of the sphere of the first pad, and the tip of the droplet of the second pad faces the nearest first pad.

In one possible design, the welding surface is provided with a plurality of grooves, the grooves are arranged in one-to-one correspondence with a plurality of bonding pads, and each bonding pad is respectively located in the corresponding groove.

The chip packaging structure provided by the utility model has the beneficial effects that: compared with the prior art, the chip packaging structure provided by the utility model has the advantages that the second distance is larger than the first distance, or the third distance is larger than the first distance, or both the second distance and the third distance are larger than the first distance, and the short circuit between the bonding pad of the peripheral bonding area and the adjacent bonding pad (the second bonding pad or the first bonding pad) is reduced to a certain extent by making at least one of the second distance and the third distance larger than the first distance.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments or the description of the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a chip package structure according to an embodiment of the present utility model;

FIG. 2 is an enlarged schematic view at A in FIG. 1;

FIG. 3 is a schematic view of a substrate of a chip package structure according to an embodiment of the present utility model;

fig. 4 is a schematic structural diagram of a chip package structure according to an embodiment of the present utility model;

fig. 5 is a schematic structural diagram of a chip package structure according to a second embodiment of the present utility model;

fig. 6 is a schematic structural diagram of a chip package structure according to a third embodiment of the present utility model;

fig. 7 is a schematic structural diagram of a chip package structure according to a fourth embodiment of the present utility model;

fig. 8 is a schematic structural diagram of a chip package structure according to a fifth embodiment of the present utility model;

fig. 9 is a schematic structural diagram of a chip package structure according to a sixth embodiment of the present utility model;

fig. 10 is a schematic structural diagram of a chip package structure according to a seventh embodiment of the present utility model.

Reference numerals related to the above figures are as follows:

10. a substrate; 20. a welding surface; 21. a peripheral weld zone; 22. an inner weld zone; 30. a bonding pad; 31. corner pads; 32. a middle section bonding pad; 321. an end pad; l1, a first distance; l2, a second distance; l3, third distance.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the utility model is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

It will be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are merely for convenience in describing and simplifying the description based on the orientation or positional relationship shown in the drawings, and do not indicate or imply that the structures or elements being referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the utility model.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In order to explain the technical scheme of the utility model, the following is a detailed description with reference to the specific drawings and embodiments.

The whole bottom surface of the BGA package can be used as a pin to be connected with a chip, and a plurality of solder balls are generally distributed on the bottom surface of the common BGA package, and the BGA package is mainly connected with corresponding welding spots on the chip through the plurality of solder balls respectively. In the related art, SMT (Surface Mounted Technology, surface mount technology) is generally used to implement electronic assembly, and in SMT production, a reflow soldering method is mainly used to solder a chip onto a BGA package, specifically, a solder ball fixed onto the BGA package is melted first, then a corresponding solder joint on the chip is contacted with the melted solder ball, and after the solder ball is cooled and solidified, the chip is soldered onto the BGA package. However, as the precision of electronic chips increases, the density of solder balls distributed on the bottom surface of the BGA package increases, and the pitch between adjacent solder balls decreases, in SMT production, a short circuit often occurs between the solder balls located in the peripheral region of the BGA package and the adjacent solder balls.

To solve the above-mentioned problems of the conventional BGA package, an embodiment of the present utility model provides a chip package structure. In order to explain the technical scheme of the utility model, the following is a detailed description with reference to the specific drawings and embodiments.

As shown in fig. 1 to 3, the chip package structure provided in one embodiment of the present utility model includes a substrate 10, the substrate 10 has a bonding surface 20, the bonding surface 20 includes an inner bonding area 22 and a peripheral bonding area 21, the peripheral bonding area 21 is surrounded by the inner bonding area 22, a plurality of bonding pads 30 are distributed on the inner bonding area 22 and the peripheral bonding area 21 at intervals, the bonding pads 30 located in the inner bonding area 22 are first bonding pads, and the bonding pads 30 located in the peripheral bonding area 21 are second bonding pads. The distance between the two nearest first bonding pads is a first distance L1, the distance between at least two adjacent second bonding pads is a second distance L2, and the distance between at least one second bonding pad and the adjacent first bonding pad is a third distance L3. The second distance L2 is greater than the first distance L1, or the third distance L3 is greater than the first distance L1, or both the second distance L2 and the third distance L3 are greater than the first distance L1.

The substrate 10 may be a PCB (Printed Circuit Board ) or a ceramic board, and the substrate 10 may be a square plate structure, a circular plate structure, or other irregular plate structure, etc., and in the embodiment described later, is substantially a square plate structure. The substrate 10 is provided with a plurality of bonding pads 30, namely, a bonding surface 20, and the shape of the bonding surface 20 is matched with that of the substrate 10, namely, when the substrate 10 is in a square plate-shaped structure, the bonding surface 20 is a square surface, when the substrate 10 is in a circular plate-shaped structure, the bonding surface 20 is a circular surface, and when the substrate 10 is in other irregular plate-shaped structures, the bonding surface 20 is an irregular surface. The bonding pads 30 are solder balls fixed on the bonding surface 20, in the production process, firstly, a steel mesh is placed on the bonding surface 20, after solder paste is injected into meshes of the steel mesh, the steel mesh is taken away, and the solder paste in each mesh is solidified on the bonding surface 20 to form solder balls, namely, the bonding pads 30 are formed. The mesh of the steel mesh corresponds to the positions of the pads 30 where the peripheral land 21 and the inner land 22 are required to be distributed, one by one, so that the corresponding pads 30 are formed at the peripheral land 21 and the inner land 22 of the bonding face 20.

The distance between the two closest first pads is a first distance L1, specifically, the distance between the center points of the two closest first pads is the first distance L1. The distance between two adjacent second pads is a second distance L2, specifically, the distance between the center points of the two adjacent second pads is the second distance L2. The distance between the second pad and the adjacent first pad is a third distance L3, specifically, the distance between the center point of the second pad and the center point of the adjacent first pad is the third distance L3. At least one of the second distance L2 and the third distance L3 is greater than the first distance L1, and the other may be greater than the first distance L1 or equal to the first distance L1.

The greater the distance between the pads 30, the lower the likelihood of a short circuit between adjacent pads 30. In the chip packaging structure provided in this embodiment, the second distance L2 is greater than the first distance L1, or the third distance L3 is greater than the first distance L1, or both the second distance L2 and the third distance L3 are greater than the first distance L1. By making at least one of the second distance L2 and the third distance L3 larger than the first distance L1, a distance between at least one second pad and an adjacent second pad is made larger; or making the distance between at least one second bonding pad and the adjacent first bonding pad larger; or the distance between at least one second pad and an adjacent second pad is made larger, and at the same time, the distance between at least one second pad and an adjacent first pad is made larger. In summary, in the peripheral land 21, the distance between at least one second pad and the adjacent pad 30 (which may be the second pad or the first pad) is larger, so that the occurrence of short circuit between the pad 30 of the peripheral land 21 and the adjacent pad 30 is reduced to some extent.

In one possible design, the bonding surface 20 is polygonal, the second bonding pads at each corner on the bonding surface 20 are corner bonding pads 31, the second bonding pads between two adjacent corner bonding pads 31 are middle bonding pads 32, the distance between the corner bonding pads 31 and the adjacent middle bonding pads 32 is a second distance L2, and the second distance L2 is greater than the first distance L1. In this arrangement, by making the distances between the corner pads 31 and the middle pads 32 larger, respectively, the occurrence of short circuits between the corner pads 31 and their adjacent pads 30 is reduced.

In some alternative embodiments, the substrate 10 is a square plate-like structure and the bonding surface 20 is a square surface. The edge area on the welding surface 20 is a peripheral welding area 21, the inner area on the welding surface 20 surrounded by the peripheral welding area 21 is an inner welding area 22, as shown in fig. 3, the annular area between the dash-dot line and the solid line is the peripheral welding area 21, and the area surrounded by the dash-dot line is the inner welding area 22. As shown in fig. 4, each of the four corners of the bonding surface 20 is provided with one corner pad 31, and the distance between each of the corner pads 31 and the adjacent middle pad 32 is the second distance L2.

In one possible design, as shown in fig. 7, the distance between at least one middle pad 32 and an adjacent first pad is a third distance L3, the third distance L3 being greater than the first distance L1. By this arrangement, the occurrence of a short circuit between the second pad and the first pad in the peripheral region can be reduced to some extent.

In one possible design, the plurality of middle pads 32 are spaced apart from each other between every two corner pads 31, and among the plurality of middle pads 32, the middle pad 32 adjacent to the corner pad 31 is an end pad 321, and a distance between the end pad 321 and the adjacent first pad is a third distance L3. In this arrangement, the occurrence of a short circuit between the second pad located near the corner pad 31 and the corresponding adjacent first pad in the peripheral land 21 can be reduced.

In some alternative embodiments, one of the plurality of middle pads 32 that is closest to the corner pad 31 may be the end pad 321, or two, three, or more middle pads 32 that are closest to the corner pad 31 may be the end pad 321, respectively. As shown in fig. 5, a plurality of middle-section bonding pads 32 are distributed between two adjacent corner bonding pads 31 on one side of the bonding surface 20 at intervals, the plurality of middle-section bonding pads 32 are arranged at intervals along the length direction of the side of the bonding surface 20, the number of end bonding pads 321 in the plurality of middle-section bonding pads 32 of the side is two, that is, each middle-section bonding pad 32 closest to the corner bonding pad 31 in two ends of the plurality of middle-section bonding pads 32 is an end bonding pad 321, and the distance between each end bonding pad 321 and the corresponding adjacent first bonding pad is a third distance L3. Alternatively, as shown in fig. 6, the number of the end pads 321 in the plurality of middle pads 32 between two adjacent corner pads 31 is four, that is, each of the two middle pads 32 closest to the corner pad 31 in the two ends of the plurality of middle pads 32 is an end pad 321, and a distance between each end pad 321 and a corresponding adjacent first pad is a third distance L3. Alternatively, the distance between the end pad 321 and the adjacent other middle pad 32 may be the first distance L1 or the second distance L2.

The chip packaging structure provided in this embodiment is mainly used for connection with a chip, and each bonding pad 30 on the bonding surface 20 is connected with a corresponding bonding pad on the chip, so the positions of each bonding pad 30 on the bonding surface 20 need to be in one-to-one correspondence with the positions of each bonding pad on the chip. In order to reduce the occurrence of short-circuits between the pads 30 and the adjacent pads 30 in the peripheral land 21 and to enable each pad 30 to be smoothly connected to a corresponding pad on the chip, the distance between the pads 30 should not be too short or too long. In one possible design, the bonding pad 30 is spherical, the diameter of the bonding pad 30 is D, the difference between the second distance L2 and the first distance L1 is less than D/2, or the difference between the third distance L3 and the first distance L1 is less than D/2, or the difference between both the second distance L2 and the third distance L3 and the first distance L1 is less than D/2. So set up, the chip packaging structure provided by the embodiment of the utility model is compared with the existing BGA packaging structure in that: as shown in fig. 1 and 2, the dashed lines in fig. 1 and 2 indicate the positions of the pads 30 on the BGA package in the prior art, and in the chip package structure provided in the embodiment of the present utility model, at least part of the pads 30 of the peripheral land 21 on the bonding surface 20 are offset from the pads 30 in the prior art by a distance such that the distance between part of the adjacent pads 30 in the peripheral land 21 is a second distance L2, and the distance between part of the pads 30 (second pads) in the peripheral land 21 and the adjacent pads 30 (first pads) in the internal land 22 is a third distance L3. Since the difference between the second distance L2 and the first distance L1 is smaller than D/2, and the difference between the third distance L3 and the first distance L1 is also smaller than D/2, the arrangement is such that, in this embodiment, after a certain distance is offset between a portion of the bonding pads 30 in the peripheral bonding area 21 on the bonding surface 20 relative to the bonding pads 30 in the prior art, the portion of the bonding pads 30 can still be stably connected to corresponding bonding pads on the chip. In an alternative embodiment, the difference between the second distance L2 and the first distance L1 is D/4, or the difference between the third distance L3 and the first distance L1 is D/4, or the difference between both the second distance L2 and the third distance L3 and the first distance L1 is less than D/4. By doing so, the distance between a part of the bonding pads 30 and the adjacent bonding pads 30 in the peripheral bonding area 21 is properly increased, and most of the area of the bonding pads 30 is still opposite to the corresponding bonding pad positions of the chip, so that the connection between each bonding pad 30 and the corresponding bonding pad of the chip is more reliable.

In the existing BGA package, the solder balls are mainly spherical. In the chip packaging structure provided by the embodiment of the utility model, the second bonding pad can be in any shape such as a sphere, an ellipsoid, a teardrop, a cube and the like, and the shapes of the first bonding pad and the second bonding pad can be the same or different. In some alternative embodiments, at least one of the second pads is ellipsoidal and the first pad is spherical, the diameter of the spherical pad 30 being equal to the length of the major axis of the ellipsoidal pad 30. Since the diameter of the spherical pad 30 is equal to the length of the major axis of the ellipsoidal pad 30, the length of the minor axis of the ellipsoidal pad 30 must be smaller than the diameter of the spherical pad 30, so that the distance between the ellipsoidal second pad and its adjacent pad 30 is greater to some extent. In some alternative embodiments, in the peripheral land 21, the corner pads 31, the end pads 321, and the middle pad 32 between the bit and end pads 321 may each be ellipsoidal, thus further reducing the occurrence of shorts between the pads 30 in the peripheral land 21 and the adjacent pads 30. Alternatively, the first bonding pad may be ellipsoidal, so that the occurrence of a short circuit between the bonding pad 30 in the inner bonding region 22 and its adjacent bonding pad 30 is reduced to some extent.

In one possible design, the distance between at least one ellipsoidal second pad and an adjacent second pad is a second distance L2 and the distance between at least one ellipsoidal second pad and an adjacent first pad is a third distance L3. In this arrangement, since the short axis length of the ellipsoidal second pad is relatively shorter and at least one of the second distance L2 and the third distance L3 is greater than the first distance L1, the interval between the ellipsoidal second pad and the adjacent pad 30 is relatively greater in the short axis extending direction of the ellipsoidal second pad, and thus, the occurrence of a short circuit between the ellipsoidal second pad and the adjacent pad 30 in the peripheral land 21 can be further reduced.

In an alternative embodiment, as shown in fig. 8, the corner pads 31 and the end pads 321 are each ellipsoidal, and in the direction shown in fig. 8, the long axis extending direction of the end pads 321 disposed at intervals in the horizontal direction is parallel to the horizontal direction, and the long axis extending direction of the end pads 321 disposed at intervals in the vertical direction is parallel to the vertical direction. In this way, the interval between the end pad 321 and the adjacent first pad is further increased, and the occurrence of short circuit between the end pad 321 and the adjacent first pad is reduced. The long axis extending direction of the corner pad 31 is parallel to the diagonal extending direction of the corresponding corner in the bonding surface 20, so that the interval between the corner pad 31 and the adjacent end pad 321 is larger, and the occurrence of short circuit between the corner pad 31 and the adjacent end pad 321 is reduced. In other alternative embodiments, as shown in fig. 9, the long axis direction of the end pad 321 may also be parallel to the long axis direction of the corner pad 31, so that the interval between the corner pad 31 and its adjacent end pad 321 may be further increased.

In one possible design, at least one of the second pads is in the form of a droplet, the first pad and the second pad are in the form of a sphere, the length of the droplet is equal to the diameter of the sphere, and the tip of the droplet is directed towards the nearest first pad. Due to the fact that the tip of the water drop-shaped bonding pad 30 is small in size, after the water drop-shaped bonding pad 30 is melted, the space for the tip of the water drop-shaped bonding pad 30 to flow to two sides is large, short circuit between the water drop-shaped bonding pad 30 and the first bonding pad closest to the water drop-shaped bonding pad can be reduced, and due to the fact that the size of the smooth end of the water drop-shaped bonding pad 30 is large, connection between the water drop-shaped bonding pad 30 and a corresponding welding spot on a chip is reliable. As shown in fig. 10, the corner pad 31 is in a drop shape, and the tip of the corner pad 31 faces the corresponding nearest first pad, so that the distance between the corner pad 31 and the adjacent end pad 321 is increased, the occurrence of a short circuit between the corner pad 31 and the adjacent end pad 321 is reduced, and the occurrence of a short circuit between the corner pad 31 and the nearest first pad is reduced. In some alternative embodiments, the end pads 321 and the other middle pads 32 may be drop-shaped pads 30, and the tips of the pads 30 of the peripheral land 21 face the pads 30 of the inner land 22, so that the occurrence of a short circuit between the second pad and the adjacent pad 30 in the peripheral land 21 may be further reduced.

In one possible design, the bonding surface 20 is provided with a plurality of grooves, which are disposed in a one-to-one correspondence with the plurality of bonding pads 30, and each bonding pad 30 is located in a corresponding groove. By providing the grooves, after the bonding pads 30 in the grooves are melted, the melted solder paste is difficult to flow into the adjacent bonding pads 30 under the barrier of the side walls of the grooves, so that the short circuit between the bonding pads 30 of the peripheral bonding pad 21 and the adjacent bonding pads 30 can be reduced, and the short circuit between the bonding pads 30 of the inner bonding pad 22 and the adjacent bonding pads 30 can be reduced.

The above description is illustrative of the various embodiments of the utility model and is not intended to be limiting, but is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims

1. The chip packaging structure is characterized by comprising a substrate, wherein the substrate is provided with a welding surface, the welding surface comprises an inner welding area and a peripheral welding area, the peripheral welding area is arranged on the periphery of the inner welding area in a surrounding mode, a plurality of bonding pads are distributed at intervals in the inner welding area and the peripheral welding area, the bonding pads located in the inner welding area are first bonding pads, and the bonding pads located in the peripheral welding area are second bonding pads;

2. The chip package structure of claim 1, wherein the bonding surface is polygonal, the second pads at each corner on the bonding surface are corner pads, the second pads between two adjacent corner pads are middle pads, and a distance between the corner pads and the adjacent middle pads is a second distance, the second distance being greater than the first distance.

3. The chip package structure of claim 2, wherein a distance between at least one of the middle pads and an adjacent first pad is a third distance, the third distance being greater than the first distance.

4. The chip package structure of claim 3, wherein a plurality of middle pads are spaced between each two corner pads, wherein among the plurality of middle pads, the middle pad adjacent to the corner pad is an end pad, and a distance between the end pad and the adjacent first pad is a third distance.

5. The chip package structure of claim 1, wherein the bonding pad is spherical, the bonding pad has a diameter D, the second distance and the first distance have a difference of less than D/2, and/or the third distance and the first distance have a difference of less than D/2.

6. The chip package structure of claim 5, wherein a difference between the second distance and the first distance is D/4, and/or a difference between the third distance and the first distance is D/4.

7. The chip package structure of any one of claims 1-4, wherein at least one of the second pads is ellipsoidal and the first pad is spherical, the diameter of the spherical pad being equal to the length of the major axis of the ellipsoidal pad.

8. The chip package structure of claim 7, wherein a distance between at least one of the ellipsoidal second pads and an adjacent second pad is a second distance, and a distance between at least one of the ellipsoidal second pads and an adjacent first pad is a third distance.

9. The chip package structure of any one of claims 1-4, wherein at least one of the second pads is in a droplet shape, the first pad and the second pad are in a sphere shape, a length of the droplet shape is equal to a diameter of the sphere shape of the first pad, and a tip of the droplet shape of the second pad faces the nearest first pad.

10. The chip package structure of any one of claims 1-6, wherein a plurality of grooves are provided on the bonding surface, the plurality of grooves are provided in one-to-one correspondence with a plurality of bonding pads, and each bonding pad is located in a corresponding groove.