CN118471935B - Chip packaging structure and method for preparing chip packaging structure - Google Patents

Abstract

The invention provides a chip packaging structure and a preparation method of the chip packaging structure, and relates to the technical field of chip packaging, wherein the chip packaging structure comprises a substrate, a first chip, a first plastic package body, a second plastic package body and a plurality of wire bonding posts, the first chip is attached to one side of the substrate, and the first plastic package body is arranged on one side surface of the substrate; the wire bonding posts are arranged on the other side surface of the substrate; the second plastic package body is arranged on the other side surface of the substrate and is coated around the wire bonding post; each wire bonding post is at least partially exposed out of the second plastic package body and is used for being electrically connected with the circuit board. Compared with the prior art, the solder ball is replaced by the wire bonding column, the solder ball welding technology is avoided, a series of problems caused by solder ball welding are further avoided, the wire bonding column is supported and protected by the second plastic package body, the structural strength can be greatly improved, the connection effect and the connection strength are ensured, meanwhile, bridging or cavitation phenomenon cannot occur to the wire bonding column, and the conductive performance is excellent.

Description

Chip packaging structure and method for preparing chip packaging structure

Technical Field

The present invention relates to the technical field of chip packaging, and in particular to a chip packaging structure and a method for preparing the chip packaging structure.

Background Art

In the process of integrated circuit packaging, the chip is brought out through various packaging methods for I/O. The traditional I/O terminal is connected to the outside (external devices: PCB board/various electronic devices, etc.) by forming a solder ball structure on the back of the substrate. However, during the board soldering process, the solder ball and the pad of the PCB board will react quickly under high temperature conditions to form an intermetallic compound (IMC), which will cause the pad on the PCB board to be quickly consumed, resulting in problems such as solder ball solder joint breakage and delamination.

In addition, the conductivity of solder balls is relatively poor, and solder ball welding is prone to bridging and solder ball voids, which affect its conductivity. In addition, solder balls are prone to fracture and failure of solder metal during drop tests due to insufficient soldering strength.

Summary of the invention

The objectives of the present invention include, for example, providing a chip packaging structure and a method for preparing the chip packaging structure, which can avoid the use of solder ball welding technology, avoid a series of problems caused by solder ball welding, ensure the connection effect and connection strength, and have excellent conductive properties.

The embodiments of the present invention can be implemented as follows:

In a first aspect, the present invention provides a chip packaging structure, comprising:

Substrate;

A first chip, wherein the first chip is attached to one side of the substrate;

A first plastic package, which is disposed on a side surface of the substrate and covers the first chip;

A plurality of bonding posts, which are arranged on the other side surface of the substrate and protrude in a direction away from the first plastic package body;

A second plastic package body, the second plastic package body is arranged on the other side surface of the substrate and covers around the bonding post;

Wherein, each of the bonding posts is electrically connected to the substrate, and each of the bonding posts is at least partially exposed outside the second plastic package body for being electrically connected to the circuit board.

In an optional embodiment, the chip packaging structure also includes a second chip, which is attached to a surface of the substrate on a side away from the first chip, and a height of the second chip relative to the substrate is less than a height of the bonding post relative to the substrate, and the second plastic package is disposed around the second chip.

In an optional implementation, a filling glue layer is further provided between the second chip and the substrate.

In an optional embodiment, a plurality of wire bonding pads are further disposed on a surface of the substrate at a side away from the first plastic packaging body, and the plurality of wire bonding posts are connected to the plurality of wire bonding pads in a one-to-one correspondence.

In an optional embodiment, one end of the bonding post away from the substrate extends out of the second plastic packaging body and is arranged to be raised relative to a surface of one side of the second plastic packaging body away from the substrate.

In an optional embodiment, the bonding post is embedded in the second plastic package body, and a first groove is formed in a side wall of the second plastic package body, and the first groove extends to the side wall of the bonding post.

In an optional embodiment, an inner wall of the first groove on a side away from the substrate is flush with an end surface of the bonding post.

In an optional embodiment, an opening direction of the first groove is away from the center of the substrate.

In an optional embodiment, a second groove is provided in the middle of a surface of the second plastic package body away from the substrate, and a width of the second groove is configured to be greater than or equal to the electrical connection pad on the circuit board so that the electrical connection pad on the circuit board is embedded in the second groove.

In an optional embodiment, both ends of the second groove penetrate through the side wall of the second plastic package body, so that the electrical connection pad on the circuit board is partially embedded in the second groove.

In an optional embodiment, the depth of the second groove is configured to be greater than or equal to the height of the electrical connection pad on the circuit board.

In a second aspect, the present invention provides a method for preparing a chip packaging structure, which is used to prepare the chip packaging structure as described in the above embodiment, and the preparation method comprises:

A first chip is mounted on one side of the substrate;

A first plastic package is formed on one side surface of the substrate, wherein the first plastic package covers the first chip;

Bonding a plurality of bonding posts on the other side surface of the substrate, wherein the plurality of bonding posts protrude in a direction away from the first plastic package body;

A second plastic package is formed on the other side surface of the substrate, wherein the second plastic package covers around the bonding post;

Wherein, each of the bonding posts is electrically connected to the substrate, and each of the bonding posts is at least partially exposed outside the second plastic package body for being electrically connected to the circuit board.

The beneficial effects of the embodiments of the present invention include, for example:

The chip packaging structure and the preparation method of the chip packaging structure provided by the embodiment of the present invention attach the first chip to one side of the substrate, and at the same time, plastic-encapsulate the first chip to form a first plastic encapsulation body, and wire the other side surface of the substrate to form a plurality of wire bonding posts, the plurality of wire bonding posts protrude in the direction away from the first plastic encapsulation body, and a second plastic encapsulation body is formed on the other side surface of the substrate, the second plastic encapsulation body is wrapped around the wire bonding posts, wherein each wire bonding post is electrically connected to the substrate, and each wire bonding post is at least partially exposed to the second plastic encapsulation body for electrical connection with the circuit board. Compared with the prior art, the present invention uses wire bonding posts to replace solder balls, avoids the use of solder ball welding technology, and thus avoids a series of problems caused by solder ball welding, and at the same time uses the second plastic encapsulation body to support and protect the wire bonding posts, which can greatly improve the structural strength, ensure the connection effect and connection strength, and at the same time, the wire bonding posts will not have bridging or void phenomena, and have excellent conductive properties.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

FIG1 is a cross-sectional schematic diagram of a first chip packaging structure provided by an embodiment of the present invention;

FIG2 is a schematic plan view of a first chip packaging structure provided by an embodiment of the present invention;

3 is a schematic diagram of an upper plate structure of a first chip packaging structure provided by an embodiment of the present invention;

FIG4 is a cross-sectional schematic diagram of a second chip packaging structure provided by an embodiment of the present invention;

FIG5 is a schematic plan view of a second chip packaging structure provided by an embodiment of the present invention;

6 is a schematic diagram of an upper plate structure of a second chip packaging structure provided by an embodiment of the present invention;

7 is a cross-sectional schematic diagram of a third chip packaging structure provided by an embodiment of the present invention;

8 is a schematic diagram of an upper plate structure of a third chip packaging structure provided by an embodiment of the present invention;

FIG9a is a schematic diagram of an upper plate plan view of a third chip packaging structure provided by an embodiment of the present invention;

Fig. 9b is a schematic diagram of the cross-sectional structure at A-A in Fig. 9a;

FIG10 is a first partial enlarged schematic diagram of X in FIG8;

FIG11 is a second partial enlarged schematic diagram of X in FIG8;

12 to 16 are process flow charts of a method for preparing a chip packaging structure provided in an embodiment of the present invention.

Icon: 100-chip packaging structure; 110-substrate; 111-wire bonding pad; 120-first chip; 130-first plastic package; 140-second plastic package; 141-first groove; 143-second groove; 150-wire bonding column; 160-second chip; 161-filling glue layer; 170-groove; 200-circuit board; 210-electrical connection pad; 230-conductive glue layer.

DETAILED DESCRIPTION

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

As disclosed in the background technology, conventional packaging devices in the prior art usually use solder ball welding technology, that is, after solder balls are planted on the back of the substrate to form solder balls, the solder balls are used to solder and fix with external devices (such as circuit boards). However, due to the characteristics of solder balls, during the soldering process on the upper board, the solder balls and the pads of the circuit board will react quickly under high temperature conditions to form intermetallic compounds (IMCs), which will cause the pads on the PCB to be quickly consumed, resulting in problems such as solder ball solder joints breaking and delamination.

In addition, the conductivity of solder balls is relatively poor, and solder ball welding is prone to bridging and solder ball voids, which affect its conductivity. In addition, solder balls are prone to fracture and failure of solder metal during drop tests due to insufficient soldering strength.

In view of this, a pin-type structure has emerged in the prior art, which uses metal bumps or metal columns to achieve upper board welding. However, this structure still requires high-temperature welding and is also prone to welding failure problems. In addition, the connection structure strength between the metal bumps or metal columns and the substrate or chip is low and is prone to falling off, which also affects its conductive performance.

To this end, an embodiment of the present invention provides a chip packaging structure and a method for preparing the chip packaging structure. It should be noted that the features in the embodiments of the present invention can be combined with each other without conflict.

Please refer to Figures 1 to 3. An embodiment of the present invention provides a chip packaging structure 100, which can avoid the use of solder ball welding technology, avoid a series of problems caused by solder ball welding, ensure the connection effect and connection strength, and have excellent conductive performance.

The chip packaging structure 100 provided in the embodiment of the present invention includes a substrate 110, a first chip 120, a first plastic package body 130, a second plastic package body 140 and a plurality of bonding posts 150. The first chip 120 is attached to one side of the substrate 110, the first plastic package body 130 is arranged on one side surface of the substrate 110 and covers the first chip 120; the plurality of bonding posts 150 are arranged on the other side surface of the substrate 110 and protrude in a direction away from the first plastic package body 130; the second plastic package body 140 is arranged on the other side surface of the substrate 110 and covers around the bonding posts 150; wherein each bonding post 150 is electrically connected to the substrate 110, and each bonding post 150 is at least partially exposed from the second plastic package body 140 for being electrically connected to the circuit board 200.

It should be noted that in this embodiment, a plurality of bonding posts 150 are arranged at intervals around the edge area of the substrate 110, and each bonding post 150 is surrounded by a second plastic package 140, which can effectively protect the bonding posts 150. Using the bonding posts 150 to replace the solder balls avoids the use of solder ball welding technology, thereby avoiding a series of problems caused by solder ball welding. At the same time, using the second plastic package 140 to support and protect the bonding posts 150 can greatly improve the structural strength, ensure the connection effect and connection strength, and at the same time, the bonding posts 150 will not have bridging or voids, and have excellent conductive properties.

Furthermore, in some embodiments, the chip package structure 100 further includes a second chip 160, which is attached to a side surface of the substrate 110 away from the first chip 120, and the height of the second chip 160 relative to the substrate 110 is less than the height of the bonding pillar 150 relative to the substrate 110, and the second plastic package 140 is arranged around the second chip 160. Specifically, the second chip 160 is flip-mounted on the bottom side surface of the substrate 110, and the first chip 120 is flip-mounted on the top side surface of the substrate 110, and the first chip 120 and the second chip 160 are aligned and arranged opposite to each other on the front side, and the mounting process of the first chip 120 and the second chip 160 can refer to the conventional chip mounting process.

It should be noted that the second chip 160 is attached to the central area of the substrate 110, and the second plastic package 140 can be arranged around the second chip 160 in the shape of a wall, and at the same time cover the plurality of wire bonding posts 150. The second plastic package 140 can be prepared by a special plastic package mold, or the central area can be removed by laser grooving or etching grooving after plane plastic packaging, thereby forming a wall structure.

In some embodiments, a filling glue layer 161 is further provided between the second chip 160 and the substrate 110. Specifically, the filling glue layer 161 can cover the bumps at the bottom of the second chip 160 and the pads on the substrate 110, thereby playing a protective role. In addition, the second plastic package 140 is also arranged around the filling glue layer 161, and the height of the filling glue layer 161 relative to the substrate 110 is lower than the height of the second chip 160 relative to the substrate 110.

In some embodiments, a plurality of wire bonding pads 111 are further provided on the surface of one side of the substrate 110 away from the first plastic package body 130, and a plurality of wire bonding posts 150 are connected to the plurality of wire bonding pads 111 in a one-to-one correspondence. Specifically, the electrical connection between the wire bonding posts 150 and the substrate 110 can be achieved through the plurality of wire bonding pads 111, and the plurality of wire bonding pads 111 can be formed together when preparing the substrate 110, so as to facilitate the subsequent wire bonding process directly on the wire bonding pads 111. Among them, the plurality of wire bonding pads 111 can be distributed along a rectangular frame and along the edge area of the substrate 110, so as to ensure that the plurality of wire bonding posts 150 formed subsequently can be arranged around the second chip 160.

In some embodiments, one end of the bonding post 150 away from the substrate 110 extends out of the second plastic package body 140, and is convexly arranged relative to the side surface of the second plastic package body 140 away from the substrate 110. Specifically, the height of the second plastic package body 140 relative to the substrate 110 is lower than the height of the bonding post 150 relative to the substrate 110. The second plastic package body 140 can protect the bonding post 150 and improve its strength. In addition, there is a height difference between the end face of the bonding post 150 and the side surface of the second plastic package body 140 away from the substrate 110. Therefore, a convex point structure can be formed at the end of the bonding post 150 away from the substrate 110, which facilitates the entry of the glue layer when the board is mounted, thereby greatly improving the bonding strength.

It should be noted that, when actually mounting the board, the end face of the bonding post 150 can directly contact the electrical connection pad 210 on the circuit board 200, that is, the bonding post 150 is connected to the electrical connection pad 210, and then fixed by an external adhesive layer, at which time the adhesive layer can preferably be a conductive adhesive layer 230, and of course, it can also be an insulating adhesive. Since the end face of the bonding post 150 protrudes from the second plastic package 140, and the end face of the bonding post 150 directly contacts the electrical connection pad 210 on the circuit board 200, a gap can be formed between the second plastic package 140 and the circuit board 200, and the adhesive layer can enter the gap, thereby increasing the coverage area of the adhesive layer, thereby improving the connection bonding and ensuring the connection strength.

In some embodiments, a plurality of grooves 170 are further provided on the end surface of the second plastic packaging body 140 away from the substrate 110. The plurality of grooves 170 are arranged at intervals on the end surface of the second plastic packaging body 140. When the board is mounted, the adhesive layer can be filled into the grooves 170, thereby greatly increasing the bonding area and further improving its bonding strength.

Referring to FIG. 4 to FIG. 6 , in some preferred embodiments, the bonding post 150 is embedded in the second plastic package body 140, and the side wall of the second plastic package body 140 is provided with a first groove 141, and the first groove 141 extends to the side wall of the bonding post 150. Specifically, the second plastic package body 140 is covered on the outside of the bonding post 150, and the first groove 141 is provided at the side wall of the second plastic package body 140, and can partially expose the bonding post 150, so as to facilitate the entry of the adhesive layer and contact with the bonding post 150, wherein the first groove 141 can allow the conductive adhesive layer 230 to enter on the one hand, so as to realize the electrical connection between the bonding post 150 and the electrical connection pad 210, and on the other hand, the first groove 141 can also play the role of a buffer groove, which can buffer the external impact on the second plastic package body 140, prevent it from cracking or falling off, and can buffer the impact between the electrical connection pad 210.

It should be noted that, when the board is actually mounted, since the bonding post 150 is embedded in the second plastic package 140, the bonding post 150 does not directly contact the electrical connection pad 210 on the circuit board 200. At this time, the side surface of the second plastic package 140 away from the substrate 110 is in direct contact with the electrical connection pad 210 on the circuit board 200, and there is also a gap between the second plastic package 140 and the circuit board 200. In order to achieve electrical connection between the pad and the bonding post 150, a conductive adhesive layer 230 can be used as a structural adhesive layer to be coated between the pad and the bonding post 150. During the flow stage of the conductive adhesive layer 230, the conductive adhesive layer 230 can flow through the first groove 141 to contact the bonding post 150, and can flow to the gap between the second plastic package 140 and the circuit board 200 to contact the pad, so the bonding post 150 can be electrically connected to the pad through the conductive adhesive layer 230.

Furthermore, the inner wall of the first groove 141 on one side away from the substrate 110 is flush with the end face of the bonding post 150. Specifically, the first groove 141 is located near the end face of the second plastic package body 140 away from the substrate 110, and can be kept flush with the end face of the bonding post 150. On the one hand, it can ensure that the conductive adhesive layer 230 can climb to the side wall of the second plastic package body 140 and enter the first groove 141 when the board is mounted, and on the other hand, it also makes the first groove 141 as far away from the first substrate 110 as possible to facilitate molding.

In some embodiments, the opening direction of the first groove 141 is away from the center of the substrate 110. Specifically, the opening direction of each first groove 141 is outward, so that the conductive adhesive layer 230 can enter the first groove 141 as quickly as possible during dispensing. Of course, in other preferred embodiments of the present invention, the opening direction of the first groove 141 can also be inward, or inclined/spiral, and the opening method of the first groove 141 is not specifically limited here.

It should be noted that the preparation of the first groove 141 here can be directly formed by a special plastic packaging mold, or the first groove 141 can be formed by slotting the side wall of the second plastic packaging body 140 through a laser slotting process. The first groove 141 is designed on the side wall of the second plastic packaging body 140, and the first groove 141 is used to penetrate to the wire post 150, so as to form a buffer structure. When the board is mounted, the conductive adhesive layer 230 at the bottom can enter the first groove 141 and the gap between the second plastic packaging body 140 and the circuit board 200 through capillary action, so as to realize the electrical connection between the wire post 150 and the pad of the circuit board 200 through the conductive adhesive layer 230. The setting of the first groove 141 and the gap can make the distribution area of the conductive adhesive layer 230 larger, greatly improve the bonding force of the conductive adhesive layer 230, and make the overall connection effect and strength better.

Referring to FIG. 7 and FIG. 8 , in some embodiments, a second groove 143 is provided in the middle of the side surface of the second plastic package 140 away from the substrate 110, and the width of the second groove 143 is configured to be greater than or equal to the electrical connection pad 210 on the circuit board 200, so that the electrical connection pad 210 on the circuit board 200 is embedded in the second groove 143. Specifically, the side wall of the second plastic package 140 is formed with a first groove 141, and the second groove 143 is formed on the side surface away from the substrate 110. The second groove 143 can improve the bonding force of the bottom glue layer on the one hand, and can fit the external pad on the circuit board 200 inside, thereby improving the positioning accuracy. Preferably, the depth of the second groove 143 is configured to be greater than or equal to the height of the electrical connection pad 210 on the circuit board 200, so as to ensure that the second groove 143 can accommodate the pad, and ensure that the second plastic package 140 is in direct contact with the circuit board 200, so as to play a supporting effect.

It is worth noting that, in this embodiment, the second groove 143 is preferably configured to match the shape of the pad, that is, the width of the second groove 143 is substantially the same as the width of the pad (with a slight installation gap margin), and the depth of the second groove 143 is the same as the height of the pad, so that accurate positioning can be further ensured, as shown in FIG10. Of course, in other preferred embodiments, the second groove 143 can also be configured to be larger than the size of the pad, that is, the width of the second groove 143 is greater than the width of the pad, and a gap can be formed between the sidewall of the second groove 143 and the electrical connection pad 210, and the depth of the second groove 143 is greater than the height of the electrical connection pad 210, as shown in FIG11. This structure can greatly increase the flow space of the bottom conductive adhesive layer 230, improve its fluidity, and thus improve the bonding force of the adhesive layer while ensuring the positioning and mounting accuracy.

Furthermore, both ends of the second groove 143 penetrate the side wall of the second plastic package 140, so that the electrical connection pad 210 on the circuit board 200 is partially embedded in the second groove 143. Specifically, both ends of the second groove 143 are through structures, so that they can be connected with the external space, which facilitates the conductive adhesive layer 230 to enter the second groove 143 through capillary action and connect with the pad.

Please continue to refer to FIG. 9a and FIG. 9b. It should be noted that the electrical connection pad 210 on the circuit board 200 here can be a strip pad, and the second groove 143 can be just buckled on the strip pad, which greatly improves the positioning effect. The second groove 143 is used to be mounted and fixed on the position of the electrical connection pad 210, thereby improving the positioning accuracy and increasing the flow space of the bottom conductive adhesive layer 230, thereby improving the bonding force of the bottom pad.

Further, as shown in Figures 9a and 9b, in an embodiment, the second plastic package body 140 can be intermittently distributed, that is, the second plastic package body 140 is only distributed around the wire bonding column 150. At this time, the first groove 141 can be opened on the side wall of the second plastic package body 140 in any direction. Preferably, the opening direction of the first groove 141 can be parallel to the extension direction of the strip-shaped electrical connection pad 210. Through this arrangement, the conductive adhesive layer 230 can be directly coated around the bottom of the second plastic package body 140 and enter the first groove 141. Compared with the aforementioned embodiment, the contact area between the conductive adhesive layer 230 and the electrical connection pad 210 can be increased here, and the distance between the first groove 141 and the electrical connection pad 210 is reduced, which can reduce the distance of the conductive path and thereby improve the electrical connection performance.

The embodiment of the present invention further provides a method for preparing a chip packaging structure 100, which is used to prepare the aforementioned chip packaging structure 100. The method comprises the following steps:

S1: placing a first chip 120 on one side of the substrate 110 .

Referring to FIG. 12 , specifically, a substrate 110 is first provided, on which a wire bonding pad 111 may be pre-prepared, and a connection pad is also pre-prepared in the chip mounting area, and then a first chip 120 is flip-chip mounted on a surface of one side of the substrate 110 through a conventional chip mounting process. Of course, the first chip 120 may also be a face-up chip, and be electrically connected to the substrate 110 through wire bonding. The substrate 110 may be a ceramic board, a lead frame, or the like.

S2: forming a first plastic package 130 on one side surface of the substrate 110 , wherein the first plastic package 130 covers the first chip 120 .

13 , specifically, a first plastic package 130 is formed on one side surface of the substrate 110 through a plastic packaging process, wherein the first plastic package 130 can cover the first chip 120 , and the first plastic package 130 is used to protect the mounted first chip 120 .

S3: bonding the other surface of the substrate 110 to form a plurality of bonding posts 150 , wherein the plurality of bonding posts 150 protrude in a direction away from the first plastic package body 130 .

Specifically, referring to FIG. 14 , after the first plastic package 130 is completed, the substrate 110 can be turned over, and then a wire bonding process is used to bond vertical metal wires on the wire bonding pads 111 on the back of the substrate 110 to form a plurality of wire bonding posts 150. The wire bonding posts 150 can be made of materials such as copper wires, aluminum wires or gold wires.

S4 : forming a second plastic package body 140 on the other side surface of the substrate 110 , and the second plastic package body 140 covers around the bonding pillars 150 .

Referring to FIG. 15 , specifically, the wire bonding structure can be encapsulated by a plastic encapsulation process to form a second plastic encapsulation body 140, and then the plastic encapsulation material at the top of the wire bonding post 150 can be removed by laser grooving to expose the end of the wire bonding post 150, so that the height of the second plastic encapsulation body 140 is lower than the height of the wire bonding post 150. Each wire bonding post 150 is electrically connected to the substrate 110, and each wire bonding post 150 is at least partially exposed outside the second plastic encapsulation body 140 for being electrically connected to the circuit board 200.

S5 : mounting the second chip 160 on the other surface of the substrate 110 .

Referring to FIG. 16 , specifically, the second chip 160 can be flip-chip mounted on the surface of the substrate 110 and located at the center of the second plastic package 140. The second chip 160 is fixed and protected by a filling glue layer 161, and has no plastic sealing glue layer, which can improve its heat dissipation performance. Finally, a cutting process is used to cut along the cutting path to separate into individual products.

In summary, the chip packaging structure 100 and the preparation method of the chip packaging structure 100 provided in the embodiment of the present invention attach the first chip 120 to one side of the substrate 110, and at the same time, plastic-encapsulate the first chip 120 to form a first plastic encapsulation body 130, and wire-bond the other side surface of the substrate 110 to form a plurality of bonding posts 150, and the plurality of bonding posts 150 protrude in a direction away from the first plastic encapsulation body 130, and a second plastic encapsulation body 140 is formed on the other side surface of the substrate 110, and the second plastic encapsulation body 140 is wrapped around the bonding posts 150, wherein each bonding post 150 is electrically connected to the substrate 110, and each bonding post 150 is at least partially exposed from the second plastic encapsulation body 140 for being electrically connected to the circuit board 200. Compared with the prior art, the present invention utilizes a bonding post 150 to replace a tin ball, thereby avoiding the use of tin ball welding technology, thereby avoiding a series of problems caused by tin ball welding. At the same time, the second plastic package 140 is used to support and protect the bonding post 150, which can greatly improve the structural strength and ensure the connection effect and connection strength. At the same time, the bonding post 150 will not have bridging or void phenomena, and has excellent conductive performance.

The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (11)

1. A chip packaging structure, comprising: Substrate; A first chip, wherein the first chip is attached to one side of the substrate; A first plastic package, which is disposed on a side surface of the substrate and covers the first chip; A plurality of bonding posts, which are arranged on the other side surface of the substrate and protrude in a direction away from the first plastic package body; A second plastic package body, the second plastic package body is arranged on the other side surface of the substrate and covers around the bonding post; The chip packaging structure further includes a second chip, the second chip is attached to a surface of the substrate facing away from the first chip, and the second plastic package is spaced apart from the second chip and surrounds the second chip, each of the bonding posts is electrically connected to the substrate, and each of the bonding posts is at least partially exposed from the second plastic package for electrical connection to a circuit board; The bonding post is embedded in the second plastic package body, and a first groove is formed on the side wall of the second plastic package body, and the first groove extends to the side wall of the bonding post; Alternatively, a plurality of grooves are further provided on the end surface of the second plastic packaging body away from the substrate, and the plurality of grooves are arranged at intervals on the end surface of the second plastic packaging body. 2 . The chip packaging structure according to claim 1 , wherein a height of the second chip relative to the substrate is smaller than a height of the bonding post relative to the substrate, and the second plastic package is disposed around the second chip. 3 . The chip packaging structure according to claim 2 , wherein a filling glue layer is further provided between the second chip and the substrate. 4. The chip packaging structure according to claim 1 or 2 is characterized in that a plurality of wire bonding pads are further provided on a surface of the substrate away from the first plastic package body, and the plurality of wire bonding posts are connected to the plurality of wire bonding pads in a one-to-one correspondence. 5 . The chip packaging structure according to claim 4 , wherein one end of the bonding post away from the substrate extends out of the second plastic package body and is protruded relative to a surface of one side of the second plastic package body away from the substrate. 6 . The chip packaging structure according to claim 1 , wherein an inner wall of the first groove on a side away from the substrate is flush with an end surface of the bonding post. 7 . The chip packaging structure according to claim 1 , wherein an opening direction of the first groove is away from a center of the substrate. 8. The chip packaging structure according to claim 1 is characterized in that a second groove is provided in the middle of a surface of a side of the second plastic package away from the substrate, and a width of the second groove is configured to be greater than or equal to the electrical connection pad on the circuit board so that the electrical connection pad on the circuit board is embedded in the second groove. 9 . The chip packaging structure according to claim 8 , wherein two ends of the second groove penetrate through the side wall of the second plastic package body, so that the electrical connection pad on the circuit board is partially embedded in the second groove. 10 . The chip packaging structure according to claim 8 , wherein a depth of the second groove is configured to be greater than or equal to a height of an electrical connection pad on the circuit board. 11. A method for preparing a chip packaging structure, for preparing the chip packaging structure according to claim 1, characterized in that the preparation method comprises: A first chip is mounted on one side of the substrate; A first plastic package is formed on one side surface of the substrate, wherein the first plastic package covers the first chip; Bonding a plurality of bonding posts on the other side surface of the substrate, wherein the plurality of bonding posts protrude in a direction away from the first plastic package body; A second plastic package is formed on the other side surface of the substrate, wherein the second plastic package covers around the bonding post; Wherein, each of the bonding posts is electrically connected to the substrate, and each of the bonding posts is at least partially exposed outside the second plastic package body for being electrically connected to the circuit board.