Chip package structure and chip package method

Abstract

The application belongs to the technical field of chip packaging, and particularly relates to a chip packaging structure, which comprises a circuit board (1) and an IC chip (2) mounted on the circuit board (1), a first tin paste (31) is arranged on the surface of the circuit board (1), the first tin paste (31) is arranged around the periphery of the IC chip (2) or under the IC chip (2), and a solid adhesive (4) is arranged on the first tin paste (31), and the solid adhesive (4) is used for bonding the IC chip (2) to the circuit board (1). The application can fix the position of the solid adhesive, prevent the solid adhesive from being displaced before the IC chip is bonded to the circuit board, and help to improve the packaging effect of the chip. In addition, the application further discloses a chip packaging method.

Description

Technical Field

[0001] This invention belongs to the technical field of chip packaging, specifically relating to a chip packaging structure and a chip packaging method. Background Technology

[0002] With the widespread application and rapid development of mobile terminals and consumer electronics products, chip size is gradually decreasing, while better heat dissipation is required to meet the demands of fast charging. This necessitates smaller, thinner, lighter circuit chips, higher current handling, lower on-resistance, and better heat dissipation.

[0003] However, since external electrical connections are provided using leadframe pins, additional pin space is required, increasing the original chip area by at least 20%. Internal electrical connections using metal wires within the packaged chip are difficult to guarantee high current handling, low on-resistance, and also limit heat dissipation. In other circuit chips, flip-chip bonding to leadframes provides high current capability, but the leadframes still require additional pin space, resulting in a larger package area.

[0004] The inventors discovered that existing packaging solutions still have at least the following drawbacks: before the IC chip is bonded to the circuit board, the adhesive between the two is prone to displacement, affecting the chip packaging effect. Summary of the Invention

[0005] One of the objectives of this invention is to provide a chip packaging structure that addresses the shortcomings of existing technologies, thereby fixing the position of the solid adhesive and preventing it from shifting before the IC chip is bonded to the circuit board, thus improving the chip packaging effect.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A chip packaging structure includes a circuit board and an IC chip mounted on the circuit board. A first solder paste is disposed on the surface of the circuit board, surrounding or below the IC chip. A solid adhesive is disposed on the first solder paste for bonding the IC chip to the circuit board.

[0008] As an improvement to the chip packaging structure described in this invention, the circuit board and the surface corresponding to the IC chip are uniformly provided with a plurality of grooves, and the grooves are provided with a second solder paste.

[0009] As an improvement to the chip packaging structure described in this invention, at least a portion of the grooves form a matrix.

[0010] As an improvement to the chip packaging structure described in this invention, the circuit board is further provided with a plurality of wires, and at least a portion of the grooves are electrically connected to the wires.

[0011] As an improvement to the chip packaging structure described in this invention, the solid adhesive is spaced around the circuit board and the IC chip.

[0012] As an improvement to the chip packaging structure described in this invention, a portion of the solid adhesive extends to the inner and / or outer side of the IC chip.

[0013] As an improvement to the chip packaging structure described in this invention, the solid adhesive located at or below the corner of the IC chip forms a strip structure.

[0014] As an improvement to the chip packaging structure described in this invention, the first solder paste is in the shape of dots or strips, and the solid adhesive is in the shape of strips or sheets.

[0015] The second objective of this invention is to provide a chip packaging method, comprising:

[0016] The first solder paste is printed on the circuit board such that it surrounds or is placed under the IC chip.

[0017] Place the solid adhesive on top of the first solder paste;

[0018] During reflow soldering, the solid adhesive is heated, melted, and cured, causing a portion of the solid adhesive to extend to the inside of the IC chip and another portion to extend to the outside of the IC chip.

[0019] It should be noted that in the packaging method of the present invention, a printing press is used to print the first solder paste on the circuit board, surrounding the surface of the circuit board corresponding to the IC chip or located below the IC chip. The first solder paste can be printed in dots and is used to fix the solid adhesive. A pick-and-place machine is used to fix the strip of solid adhesive onto the first solder paste. Finally, reflow soldering is performed, heating the solid adhesive to melt it, with some flowing into the bottom of the IC chip. The solid adhesive solidifies, with some extending to the inner side of the IC chip and another part extending to the outer side of the IC chip, filling the gap between the IC chip and the circuit board, enabling the IC chip to bond to the circuit board, ensuring the reliability of the connection between the IC chip and the circuit board, and helping to improve the quality of the finished product. The first solder paste and the second solder paste can be pre-printed on the circuit board. An optical inspection device is used to determine whether the positions of the first solder paste and the second solder paste are accurate. Then, solid adhesive is placed on top of the first solder paste, and finally the IC chip is soldered onto the circuit board. The first solder paste serves to fix the solid adhesive, and the second solder paste is used to solder the IC chip onto the circuit board.

[0020] As an improvement to the chip packaging method described in this invention, the maximum temperature of the reflow soldering is 180℃~270℃.

[0021] The beneficial effects of this invention are as follows: This invention includes a circuit board and an IC chip mounted on the circuit board. A first solder paste is disposed on the surface of the circuit board, surrounding or below the IC chip. A solid adhesive is disposed on the first solder paste, used to bond the IC chip to the circuit board. Since the adhesive between the IC chip and the circuit board is prone to displacement before bonding, affecting the chip packaging effect, the circuit board surface is provided with a first solder paste, on which a solid adhesive is disposed. The first solder paste can be printed on the surface of the circuit board using a printer, surrounding the surface of the circuit board corresponding to the IC chip, or disposed below the IC chip. During reflow soldering, the solid adhesive melts upon heating, partially flowing into the IC chip to bond the IC chip to the circuit board, reducing the probability of poor soldering between the IC chip and the circuit board. The solid adhesive is solid and has a multi-layered structure. Since the solid adhesive itself is not adhesive, it is placed on the first solder paste, which acts as a fixative for the solid adhesive. During chip packaging, the heated and melted solid adhesive... The adhesive material bonds the IC chip to the circuit board and fills the gap between the IC chip and the circuit board, improving the mechanical properties of the packaging structure, firmly fixing the IC chip, and preventing displacement due to mechanical vibration during use. This contributes to improving the battery cell packaging effect and extending the lifespan of electronic products. The gap between the IC chip and the circuit board is not limited to the edge of the IC chip; since some IC chips are not soldered to the circuit board in the center, a gap also exists. Therefore, the surfaces of the circuit board corresponding to the center of the IC chip can be coated with a first solder paste and a solid adhesive. The first solder paste can be printed in dots, and its size can be adjusted according to the actual size of the circuit board to fix the solid adhesive. This invention can fix the position of the solid adhesive, preventing displacement before the IC chip is bonded to the circuit board, thus improving the chip packaging effect. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention before packaging.

[0023] Figure 2 This is a schematic diagram of the packaged structure of the present invention.

[0024] Wherein: 1-Circuit board; 2-IC chip; 31-First solder paste; 32-Second solder paste; 4-Solid adhesive; 21-Groove. Detailed Implementation

[0025] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" as used throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.

[0026] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] The present invention will be further described in detail below with reference to the accompanying drawings, but this is not intended to limit the scope of the invention.

[0029] Example 1

[0030] like Figures 1-2As shown, a chip packaging structure includes a circuit board 1 and an IC chip 2 mounted on the circuit board 1. A first solder paste 31 is provided on the surface of the circuit board 1. The first solder paste 31 is disposed around the IC chip 2 or below the IC chip 2. A solid adhesive 4 is disposed on the first solder paste 31. The solid adhesive 4 is used to bond the IC chip 2 to the circuit board 1. Because the adhesive between IC chip 2 and circuit board 1 is prone to displacement before bonding, affecting the chip packaging effect, a first solder paste 31 is applied to the surface of circuit board 1, and a solid adhesive 4 is applied to the first solder paste 31. The first solder paste 31 can be printed on the surface of circuit board 1 using a printer, surrounding the surface of circuit board 1 corresponding to IC chip 2, or placed below IC chip 2. During reflow soldering, the solid adhesive 4 melts upon heating, and some flows into IC chip 2 to bond IC chip 2 to circuit board 1, reducing the probability of poor soldering between IC chip 2 and circuit board 1. The solid adhesive 4 is solid and has a multi-layered structure. Since the solid adhesive 4 itself is not adhesive, it is placed on the first solder paste 31, which serves to fix the solid adhesive 4. During chip packaging, the solid adhesive 4 melts upon heating. The adhesive 4 has adhesive properties, bonding the IC chip 2 to the circuit board 1. It also fills the gap between the IC chip 2 and the circuit board 1, which helps improve the mechanical performance of the packaging structure, firmly fixes the IC chip 2, and prevents the IC chip 2 from shifting due to mechanical vibration during use. This helps improve the effect of cell packaging and extend the service life of electronic products. The gap between the IC chip 2 and the circuit board 1 is not limited to the edge of the IC chip 2. Since some IC chips 2 are not soldered to the center of the circuit board 1, there is also a certain gap. Therefore, the surfaces of the circuit board 1 and the center of the IC chip 2 can also be provided with the first solder paste 31 and the solid adhesive 4. The first solder paste 31 can be printed in the form of dots, and the size of the first solder paste 31 can be adjusted according to the actual size of the circuit board 1 to achieve the effect of fixing the solid adhesive 4.

[0031] Preferably, the surfaces of the circuit board 1 and the IC chip 2 are uniformly provided with a plurality of grooves 21, and the grooves 21 are provided with second solder paste 32. During the reflow soldering process, the second solder paste 32 in the grooves 21 on the surface of the circuit board 1 melts to form pads, allowing the IC chip 2 to be electrically connected to the circuit board 1 through the pads, thereby soldering the IC chip 2 to the circuit board 1. This simplifies the production process and improves the installation efficiency of the circuit board 1 and the IC chip 2. The grooves 21 are circular in shape, but are not limited thereto. The shape and depth of the grooves 21 can be adjusted according to the actual production process requirements.

[0032] Preferably, at least a portion of the grooves 21 form a matrix. The central groove 21 forms a square matrix, and the grooves 21 surrounding this square matrix also form another square matrix, and so on. The size of each square matrix can be adjusted according to the actual circuit of the IC chip 2, but the present invention is not limited thereto. The grooves 21 can also form a circular, elliptical matrix or a hollow rectangle.

[0033] Preferably, the circuit board 1 is further provided with a plurality of wires, and at least a portion of the grooves 21 are electrically connected to the wires. The grooves 21 are electrically connected to the wires, and the grooves 21 are electrically connected to the IC chip 2 through reflow soldering, thereby realizing the connection between the IC chip 2 and the corresponding wires, and thus realizing the function of the circuit.

[0034] Preferably, the solid adhesive 4 is spaced around the circuit board 1 and the IC chip 2. This spaced arrangement of the solid adhesive 4 around the circuit board 1 and the IC chip 2 reduces the cost of the solid adhesive 4 and ensures the reliability of the connection between the IC chip 2 and the circuit board 1.

[0035] Preferably, a portion of the solid adhesive 4 extends to the inner and / or outer side of the IC chip 2. The solid adhesive 4 softens and flows along the IC chip 2, with some of it flowing into the inner side of the IC chip 2 but not contacting the pads of the circuit board 1. This does not hinder the IC chip 2 from being soldered to the circuit board 1, ensuring the reliability of the connection between the IC chip 2 and the circuit board 1. It also fills the gap between the IC chip 2 and the circuit board 1, acting as a buffer.

[0036] Preferably, the solid adhesive 4 located at or below the corners of the IC chip 2 forms a strip structure. Using several strip-shaped solid adhesive 4s placed at or below the corners of the IC chip 2 can reduce the amount of solid adhesive 4 used, thereby reducing the cost of solid adhesive 4 and ensuring the reliability of the connection between the IC chip 2 and the circuit board 1. The several strip-shaped solid adhesive 4s can be arranged in a circle or rectangle according to process requirements, and adjacent solid adhesive 4s are spaced apart.

[0037] Preferably, the first solder paste 31 is in the shape of dots, and the solid adhesive 4 is in the shape of strips. By designing the first solder paste 31 to be in the shape of dots and the solid adhesive 4 to be in the shape of strips, the solid adhesive 4 is placed on the dots formed by the first solder paste 31. It is only necessary to ensure that the solid adhesive 4 is fixed on 2 to 3 dots formed by the first solder paste 31. The solid adhesive 4 can be pre-formed and then attached to the dots formed by the first solder paste 31 by a pick and place machine.

[0038] The working principle of this invention is:

[0039] Because the adhesive between IC chip 2 and circuit board 1 is prone to displacement before bonding, affecting the chip packaging effect, a first solder paste 31 is applied to the surface of circuit board 1, and a solid adhesive 4 is applied to the first solder paste 31. The first solder paste 31 can be printed on the surface of circuit board 1 using a printer, surrounding the surface of circuit board 1 corresponding to IC chip 2, or placed below IC chip 2. During reflow soldering, the solid adhesive 4 melts upon heating, and some flows into IC chip 2 to bond IC chip 2 to circuit board 1, reducing the probability of poor soldering between IC chip 2 and circuit board 1. The solid adhesive 4 is solid and has a multi-layered structure. Since the solid adhesive 4 itself is not adhesive, it is placed on the first solder paste 31, which serves to fix the solid adhesive 4. During chip packaging, the solid adhesive 4 melts upon heating. The adhesive 4 has adhesive properties, bonding the IC chip 2 to the circuit board 1. It also fills the gap between the IC chip 2 and the circuit board 1, which helps improve the mechanical performance of the packaging structure, firmly fixes the IC chip 2, and prevents the IC chip 2 from shifting due to mechanical vibration during use. This helps improve the effect of cell packaging and extend the service life of electronic products. The gap between the IC chip 2 and the circuit board 1 is not limited to the edge of the IC chip 2. Since some IC chips 2 are not soldered to the center of the circuit board 1, there is also a certain gap. Therefore, the surfaces of the circuit board 1 and the center of the IC chip 2 can also be provided with the first solder paste 31 and the solid adhesive 4. The first solder paste 31 can be printed in the form of dots, and the size of the first solder paste 31 can be adjusted according to the actual size of the circuit board 1 to achieve the effect of fixing the solid adhesive 4.

[0040] Example 2

[0041] Unlike Embodiment 1, in this embodiment, a portion of the solid adhesive 4 extends to the inner or outer side of the IC chip 2. The first solder paste 31 is strip-shaped, and the solid adhesive 4 is sheet-shaped. Depending on actual production needs, the first solder paste 31 can be designed as a strip to increase the contact area between the first solder paste 31 and the solid adhesive 4, thus achieving better fixation of the solid adhesive 4. The solid adhesive 4 can be designed as a sheet to increase the contact area between the first solder paste 31 and the solid adhesive 4, thereby improving the reliability between them.

[0042] The other structures are the same as in Example 1, and will not be described again here.

[0043] Example 3

[0044] like Figures 1-2 As shown, a chip packaging method includes:

[0045] The first solder paste 31 is printed on the circuit board 1, such that the first solder paste 31 surrounds or is below the IC chip 2;

[0046] Place solid adhesive 4 on top of the first solder paste 31;

[0047] Through reflow soldering, the solid adhesive 4 is heated, melted, and cured, so that a portion of the solid adhesive 4 extends to the inside of the IC chip 2, and another portion of the solid adhesive 4 extends to the outside of the IC chip 2.

[0048] It should be noted that in the packaging method of the present invention, a printing press is used to print the first solder paste 31 onto the circuit board 1, surrounding the surface of the circuit board 1 corresponding to the IC chip 2 or located below the IC chip 2. The first solder paste 31 can be printed in dots, and the first solder paste 31 is used to fix the solid adhesive 4. A pick-and-place machine is used to fix the strip-shaped solid adhesive 4 onto the first solder paste 31. Finally, reflow soldering is performed, heating the solid adhesive 4 to melt it, with some flowing into the bottom of the IC chip 2. The solid adhesive 4 solidifies, with some extending to the inner side of the IC chip 2 and another part extending to the outer side of the IC chip 2, thus serving to... Filling the gap between IC chip 2 and circuit board 1 allows IC chip 2 to be bonded to circuit board 1, ensuring the reliability of the connection between IC chip 2 and circuit board 1 and helping to improve the quality of the finished product. The first solder paste 31 and the second solder paste 32 can be pre-printed on circuit board 1. The position of the first solder paste 31 and the second solder paste 32 is judged by an optical detection device to determine whether they are accurate. Then, solid adhesive 4 is placed on top of the first solder paste 31. Finally, IC chip 2 is soldered onto circuit board 1. The first solder paste 31 serves to fix the solid adhesive 4, and the second solder paste 32 is used to solder IC chip 2 onto circuit board 1.

[0049] Preferably, the maximum reflow soldering temperature is 180℃~270℃. Limiting the maximum reflow soldering temperature prevents excessively high temperatures from increasing production costs and affecting the physical properties of the second solder paste 32 and solid adhesive 4. At the same time, it prevents excessively low temperatures from causing some of the second solder paste 32 to remain solid, which is not conducive to the soldering of the second solder paste 32 to the IC chip 2 and the circuit board 1.

[0050] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above, and any obvious improvements, substitutions, or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention.

Claims

1. A chip package structure, characterized by: The application relates to a circuit board (1) and an IC chip (2) mounted on the circuit board (1), wherein the surface of the circuit board (1) is provided with a first tin paste (31), the first tin paste (31) is arranged around the periphery of the IC chip (2) or under the IC chip (2), the first tin paste (31) is provided with a solid adhesive (4), the solid adhesive (4) is used for bonding the IC chip (2) to the circuit board (1), the surface of the circuit board (1) and the IC chip (2) is uniformly provided with a plurality of grooves (21), the grooves (21) are provided with a second tin paste (32), part of the solid adhesive (4) extends to the inner side and / or the outer side of the IC chip (2), the surface of the circuit board and the IC chip is provided with the first tin paste and the solid adhesive. The circuit board (1) is further provided with a plurality of wires, at least part of the grooves (21) are electrically connected with the wires. The solid adhesive (4) is arranged outside the grooves (21). The solid adhesive is softened and flows along the IC chip, part of the solid adhesive flows into the inner side of the IC chip and does not contact the pad of the circuit board.

2. The chip package structure of claim 1, wherein: At least part of the grooves (21) form a matrix.

3. The chip package structure of claim 1, wherein: The solid adhesive (4) is arranged between the circuit board (1) and the IC chip (2).

4. The chip package structure of claim 1, wherein: The solid adhesive (4) located at the corners or under the IC chip (2) forms a strip-shaped structure.

5. The chip package structure of claim 1, wherein: The shape of the first tin paste (31) is point-shaped or strip-shaped, and the shape of the solid adhesive (4) is strip-shaped or sheet-shaped.

6. A chip packaging method using the chip packaging structure according to any one of claims 1 to 5, characterized by, The application further relates to a method for manufacturing the circuit board (1) and the IC chip (2). The first tin paste (31) is printed on the circuit board (1), so that the first tin paste (31) is arranged around the periphery or under the IC chip (2). The solid adhesive (4) is arranged on the top of the first tin paste (31). The solid adhesive (4) is heated, melted and solidified through reflow soldering, so that part of the solid adhesive (4) extends to the inner side of the IC chip (2) and part of the solid adhesive (4) extends to the outer side of the IC chip (2).

7. The method of claim 6, wherein: The highest temperature of the reflow soldering is 180-270 DEG C.

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