Chip glue injection method and semiconductor structure

Abstract

The invention discloses a chip glue injection method and a semiconductor structure, and the method comprises the steps: carrying out the first preheating of a packaging chip after the packaging chip with the bottom uniformly provided with solder balls is welded with a circuit substrate, injecting a first amount of structural glue at the corner position of the packaging chip, carrying out heat preservation for a first preset duration and then carrying out high-temperature curing treatment so as to form an initial glue injection area corresponding to each corner position; carrying out second preheating treatment on the packaged chip, injecting a second quantity of structural adhesive into the corner positions of the packaged chip, carrying out heat preservation for a second preset duration and then carrying out high-temperature curing treatment so as to form edge adhesive injection areas corresponding to the corner positions, the bonding strength and the bonding area of the edge glue injection area meet the preset bonding strength and the preset bonding area through the second quantity of structural glue and the second preset heat preservation duration. According to the method, the problem of lack of air caused by the adoption of a full-filling or basic-filling glue injection mode can be avoided, and then the stability of the bonding performance of the packaged chip is guaranteed.

Description

Technical Field

[0001] The present application relates to the field of semiconductor processing technology, and in particular to a chip glue injection method and a semiconductor structure. Background Art

[0002] For large-size automotive SOC chip types, it adopts Ball Grid Array Package (BGA) packaging technology. BGA packaging is commonly used in high-performance integrated circuits such as motherboard control chipsets and memory. It is a better choice for high-density, high-performance, multi-function and high I / O pin packaging. Most of the existing high-pin-count chips (such as graphics chips and chipsets) use BGA packaging technology.

[0003] The prior art adopts a method of completely filling or substantially filling the space between the packaged chip and the circuit substrate with structural adhesive. Due to the large injection area, the flow direction of the structural adhesive is uncontrollable. For example, structural adhesives with opposite flows may generate eddies due to intersection, thereby generating bubbles (i.e., idle air), affecting the bonding stability.

[0004] Therefore, for BAG packaged chips such as large-size automotive SOC chips, how to effectively inject structural adhesive is a problem that needs to be solved. Summary of the invention

[0005] The technical problem to be solved by the present application is to provide a chip glue injection method to solve the problem of affecting the bonding stability during the existing BAG packaging chip glue injection process.

[0006] According to one aspect of the present invention, a chip glue injection method is provided, the method comprising:

[0007] After welding the packaged chip with solder balls evenly arranged on the bottom to the circuit substrate, the packaged chip is subjected to a first preheating treatment, a first amount of structural adhesive is injected into the corners of the packaged chip, and a high-temperature curing treatment is performed after the first predetermined insulation time to form an initial injection area corresponding to each of the corners, and the first amount of structural adhesive and the first predetermined insulation time enable the initial injection area to reach a preset bonding range in the direction of the middle area of ​​the bonding surface of the packaged chip;

[0008] Performing a second preheating treatment on the packaged chip, injecting a second amount of structural adhesive into the corners of the packaged chip, and performing a high-temperature curing treatment after keeping the temperature for a second predetermined time, so as to form an edge injection area corresponding to each of the corners, and the second amount of structural adhesive and the second predetermined insulation time make the bonding strength and bonding area of ​​the edge injection area meet the preset bonding strength and preset bonding area;

[0009] The initial glue injection area and the edge glue injection area form a target glue injection area, and the interval distance between any adjacent target glue injection areas is greater than a predetermined distance threshold.

[0010] In some embodiments, the initial glue injection area is connected to the edge glue injection area.

[0011] In some embodiments, a first amount of structural adhesive is injected into the corner positions of the packaged chip, including: using an L-shaped glue injection method to inject 90±10㎎ of structural adhesive into the corner positions of the packaged chip, wherein, for each of the corner positions, the length of the starting glue injection edge of the same end angle is less than the length of the ending glue injection edge, so that the amount of structural adhesive injected toward the center area by the starting glue injection edge and the ending glue injection edge is the same.

[0012] In some embodiments, the length of the starting glue injection edge is 10 mm to 11 mm, and the length of the ending glue injection edge is 12 mm to 13 mm.

[0013] In some embodiments, injecting a second amount of structural adhesive into the corners of the packaged chip includes: injecting 6±2㎎ of structural adhesive into the corners of the packaged chip using an L-shaped adhesive injection method, wherein the lengths of two adhesive injection edges at the same end corner are 3㎜ to 5㎜.

[0014] In some embodiments, the first predetermined insulation time includes insulation for 3±1 minutes, or the second predetermined insulation time includes insulation for 3±1 minutes.

[0015] In some embodiments, the first preheating treatment of the packaged chip includes: preheating the packaged chip to 80° C. to 90° C.; or,

[0016] The performing a second preheating treatment on the packaged chip includes: preheating the packaged chip to 80° C. to 90° C.

[0017] In some embodiments, the high-temperature curing treatment is performed after the first predetermined heat preservation period, including: after the first predetermined heat preservation period, the initial glue injection area is subjected to high-temperature curing treatment at a temperature of 140° C. to 160° C. for 14 minutes to 18 minutes; or,

[0018] The high temperature curing treatment is performed after the second predetermined heat preservation period, including: after the second predetermined heat preservation period, the edge injection area is subjected to high temperature curing treatment at a temperature of 140° C. to 160° C. for a time of 14 minutes to 18 minutes.

[0019] In some embodiments, injecting a first amount of structural adhesive into the corners of the packaged chip comprises: injecting the first amount of structural adhesive into each corner of the packaged chip in a clockwise direction; or injecting a second amount of structural adhesive into the corners of the packaged chip comprises: injecting the second amount of structural adhesive into each corner of the packaged chip in a clockwise direction.

[0020] In some implementations, the predetermined distance threshold includes a spacing corresponding to 5 to 20 solder balls.

[0021] According to another aspect of the present invention, there is provided a semiconductor structure, comprising a packaged chip and a circuit substrate, wherein solder balls are evenly arranged on the bottom of the packaged chip, and the packaged chip is soldered to the circuit substrate through the solder balls, and a target glue injection area formed by injecting structural glue is included between each corner area of ​​the packaged chip and the circuit substrate, and the target glue injection area includes an initial glue injection area and an edge glue injection area, and the initial glue injection area reaches a preset bonding range in the direction of the middle area of ​​the bonding surface of the packaged chip, and the bonding strength and bonding area of ​​the edge glue injection area meet the preset bonding strength and preset bonding area, and the spacing distance between any adjacent target glue injection areas is greater than a preset distance threshold.

[0022] Compared with the prior art, this application has the following advantages:

[0023] The chip injection method provided in the embodiment of the present application includes: after welding a packaged chip with solder balls evenly arranged on the bottom to a circuit substrate, performing a first preheating treatment on the packaged chip, injecting a first amount of structural glue into the corners of the packaged chip, and performing a high-temperature curing treatment after keeping it warm for a first predetermined time to form an initial injection area corresponding to each corner position, and the first amount of structural glue and the first predetermined insulation time make the initial injection area reach a preset bonding range in the direction toward the middle area of ​​the packaged chip; performing a second preheating treatment on the packaged chip, injecting a second amount of structural glue into the corners of the packaged chip, and performing a high-temperature curing treatment after keeping it warm for a second predetermined time to form an edge injection area corresponding to each corner position, and the second amount of structural glue and the second predetermined insulation time make the bonding strength and bonding area of ​​the edge injection area meet the preset bonding strength and preset bonding area; wherein, the initial injection area and the edge injection area form a target injection area, and the spacing distance between any adjacent target injection areas is greater than a preset distance threshold. In the method, an initial glue injection area reaching a preset bonding range is formed in the direction of the central area of ​​the bonding surface through the first glue injection, and an edge glue injection area satisfying a preset bonding strength and a preset bonding area is formed corresponding to each corner position through the second glue injection, which can make up for the insufficient glue amount at the edge position caused by the structural glue flowing toward the middle of the chip during the first glue injection. Through the first and second glue injections, the bonding strength and bonding area (the bonding area at the edge position and the bonding area toward the central area of ​​the packaged chip) are effectively guaranteed, and the target glue injection area formed by the initial glue injection area and the edge glue injection area can avoid the problem of idle air caused by the glue injection method of fully filling or substantially filling due to the large chip size, thereby ensuring the stability of the bonding performance of the packaged chip.

[0024] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the following specifically cites the preferred embodiments and describes them in detail with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a process flow chart of the chip glue injection method provided in the embodiment of the present application;

[0026] Figure 2 It is a schematic diagram of chip glue injection provided in an embodiment of the present application.

[0027] Notes on the attached drawings:

[0028] 1 packaged chip, 2 circuit substrate, 3 initial injection area, 4 edge injection area. DETAILED DESCRIPTION

[0029] Many specific details are described in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present application, so the present application is not limited by the specific implementation disclosed below.

[0030] The terms used in one or more embodiments of this specification are only for the purpose of describing specific embodiments, and are not intended to limit one or more embodiments of this specification. The singular forms of "a", "said" and "the" used in one or more embodiments of this specification and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in one or more embodiments of this specification refers to and includes any or all possible combinations of one or more associated listed items.

[0031] It should be understood that although the terms first, second, etc. may be used to describe various information in one or more embodiments of this specification, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of one or more embodiments of this specification, the first may also be referred to as the second, and similarly, the second may also be referred to as the first. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0032] Regarding the chip injection process, in order to solve the problem of idle gas caused by the injection method of filling the chip completely or substantially filling the chip with large size, the embodiment of the present application provides a chip injection method, please refer to Figure 1-Figure 2 To understand this embodiment, Figure 1 is a process flow chart of the chip glue injection method provided in this embodiment; Figure 2 It is a schematic diagram of chip glue injection provided in an embodiment of the present application.

[0033] Ball Grid Array Package (BGA) is a surface mount packaging technology used in integrated circuits. The bottom of the chip in the BGA package has metal solder balls arranged in a grid-like pattern, which are connected to the pads on the circuit substrate (or printed circuit board, PCB board). Compared with dual inline packages (Dual Inline Package) or Quad Flat Package (Quad Flat Package), BGA packages can accommodate more pins, and the solder balls on the bottom surface of the entire chip can be used as pins.

[0034] During BGA packaging, when the packaged chip is fixed on the circuit substrate using surface mount technology, the bottom solder balls are arranged to correspond to the position of the copper foil on the circuit substrate. After the solder balls are dissolved, the surface tension will cause the melted solder balls to support the packaging points and align them to the circuit substrate. At the correct spacing distance, when the solder balls are cooled and fixed, the formed solder joints can connect the packaged chip and the circuit substrate.

[0035] The chip glue injection method provided in this embodiment is applied to the glue injection process after the above process, such as Figure 1 and Figure 2 As shown, the chip glue injection method provided in this embodiment includes:

[0036] S1, after welding the packaged chip 1 with solder balls evenly arranged on the bottom to the circuit substrate 2, the packaged chip 1 is subjected to a first preheating treatment, and a first amount of structural adhesive is injected into the corners of the packaged chip 1, and then the adhesive is kept warm for a first predetermined time and then subjected to a high-temperature curing treatment to form an initial adhesive injection area 3 corresponding to each corner position.

[0037] The first amount of structural adhesive and the first predetermined insulation time enable the initial injection area 3 to reach a preset bonding range in the direction toward the middle area of ​​the packaged chip 1, that is, the initial injection area can represent the extension depth of the structural adhesive toward the center of the chip.

[0038] S2, performing a second preheating treatment on the packaged chip 1, injecting a second amount of structural adhesive into the corners of the packaged chip 1, and performing a high-temperature curing treatment after keeping the temperature for a second predetermined time to form edge glue injection areas 4 corresponding to the corners.

[0039] The second amount of structural adhesive and the second predetermined insulation time make the bonding strength and bonding area of ​​the edge glue injection area 4 meet the preset bonding strength and preset bonding area;

[0040] Among them, the initial glue injection area 3 and the edge glue injection area 4 form a target glue injection area, and the spacing distance between any adjacent target glue injection areas is greater than or equal to a predetermined distance threshold, the purpose of which is to avoid a single target glue injection area being too large, or the target glue injection areas formed at different corner positions intersecting, thereby causing idle air to form in the middle of the chip. In this embodiment, the predetermined distance threshold can be a spacing corresponding to 5 to 20 solder balls. In this embodiment, the initial glue injection area is connected to the edge glue injection area to form an overall target glue injection area, that is, after the initial glue injection area is formed by high-temperature curing treatment, the initial glue injection area can be used as a boundary enclosure during the second glue injection, and the glue injection amount and glue injection area of ​​the second glue injection are determined based on this, so that the glue injection amount and insulation time of the second glue injection are more accurate, thereby effectively ensuring the bonding performance of the edge glue injection area after the second glue injection.

[0041] In another embodiment, a certain gap may be reserved between the initial glue injection area and the edge glue injection area, that is, the initial glue injection area effectively bonds the area near the middle of the chip, and the edge glue injection area effectively bonds the edge of the chip.

[0042] The first preheating treatment or the second preheating treatment is performed on the packaged chip 1 to make the packaged chip 1 in a state where the glue can be injected. In this embodiment, for a large-size SOC chip mounted on a vehicle, the packaged chip can be preheated to 80°C to 90°C, for example, 85°C, during the first preheating treatment; the packaged chip can also be preheated to 80°C to 90°C during the second preheating treatment.

[0043] The above-mentioned injecting a first amount of structural glue into the corners of the packaged chip may refer to: injecting a first amount of structural glue into each corner of the packaged chip in a clockwise direction; for example, for a large-size vehicle-mounted SOC chip, an L-shaped glue injection method is used to inject 90±10㎎ of structural glue into each corner of the packaged chip, and the needle head continuously dispenses glue at each corner and dispenses glue along an L-shaped path, so as to inject the structural glue into the solder ball gap on the welding surface between the packaged chip and the circuit substrate, wherein the length of the starting glue injection edge at each corner is less than the length of the ending glue injection edge, so that the amount of structural glue injected toward the center area by the starting glue injection edge and the ending glue injection edge is the same, for example, the length of the starting glue injection edge is 10㎜ to 11㎜, and the length of the ending glue injection edge is 12㎜ to 13㎜.

[0044] The amount of glue injected and the duration of the heat preservation treatment jointly determine the flow direction, flow rate and flow rate of the structural glue between the packaged chip 1 and the circuit substrate 2. The heat preservation time can characterize the flow time of the structural glue, which together with the amount of glue injected affects the bonding performance. When the amount of glue injected is determined, if the heat preservation time is too long, the structural glue will flow towards the middle area of ​​the chip for too long and the amount of glue flowing will be too much, which will cause the structural glue flowing from the corner areas to the middle area to intersect and cause eddy currents and generate bubbles, affecting the bonding performance; if the heat preservation time is too short, the structural glue will flow towards the middle area for too short a time and the amount of glue flowing will be too little, which cannot guarantee the effective bonding area and affects the bonding performance. In this embodiment, for large-size SOC chips on vehicles, the above-mentioned first predetermined heat preservation time can be 3±1 minutes.

[0045] For the second glue injection, the second amount of structural glue can also be injected into each corner of the packaged chip in a clockwise direction; for example, for large-size automotive SOC chips, an L-shaped glue injection method can be used to inject 6±2㎎ of structural glue into the corners of the packaged chip, wherein the lengths of the two glue injection edges at each corner can be 3㎜ to 5㎜, for example, 4㎜. Correspondingly, the above-mentioned second predetermined insulation time can be 3±1 minutes.

[0046] In this embodiment, for the large-size SOC chip mounted on a vehicle, the high-temperature curing treatment is performed after the first predetermined heat preservation period, which specifically refers to: after the first predetermined heat preservation period, the initial glue injection area is subjected to high-temperature curing treatment at a temperature of 140° C. to 160° C. for 14 minutes to 18 minutes;

[0047] The high temperature curing treatment after the second predetermined insulation period may specifically refer to: after the second predetermined insulation period, the edge injection area is subjected to high temperature curing treatment at a temperature of 140°C to 160°C for a period of 14 minutes to 18 minutes.

[0048] The chip injection method provided in the embodiment of the present application includes: after welding a packaged chip with solder balls evenly arranged on the bottom to a circuit substrate, performing a first preheating treatment on the packaged chip, injecting a first amount of structural glue into the corners of the packaged chip, and performing a high-temperature curing treatment after keeping it warm for a first predetermined time to form an initial injection area corresponding to each corner position, and the first amount of structural glue and the first predetermined insulation time make the initial injection area reach a preset bonding range in the direction toward the middle area of ​​the packaged chip; performing a second preheating treatment on the packaged chip, injecting a second amount of structural glue into the corners of the packaged chip, and performing a high-temperature curing treatment after keeping it warm for a second predetermined time to form an edge injection area corresponding to each corner position, and the second amount of structural glue and the second predetermined insulation time make the bonding strength and bonding area of ​​the edge injection area meet the preset bonding strength and preset bonding area; wherein, the initial injection area and the edge injection area form a target injection area, and the spacing distance between any adjacent target injection areas is greater than a preset distance threshold. In the method, an initial glue injection area reaching a preset bonding range is formed in the direction of the central area of ​​the bonding surface through the first glue injection, and an edge glue injection area satisfying a preset bonding strength and a preset bonding area is formed corresponding to each corner position through the second glue injection, which can make up for the insufficient glue amount at the edge position caused by the structural glue flowing toward the middle of the chip during the first glue injection. Through the first and second glue injections, the bonding strength and bonding area (the bonding area at the edge position and the bonding area toward the central area of ​​the packaged chip) are effectively guaranteed, and the target glue injection area formed by the initial glue injection area and the edge glue injection area can avoid the problem of idle air caused by the glue injection method of fully filling or substantially filling due to the large chip size, thereby ensuring the stability of the bonding performance of the packaged chip.

[0049] Another embodiment of the present application also provides a semiconductor structure, which includes a packaged chip and a circuit substrate. Solder balls are evenly arranged on the bottom of the packaged chip. The packaged chip is welded to the circuit substrate through the solder balls. Each corner area of ​​the packaged chip and the circuit substrate include a target injection area formed by injecting structural glue. The target injection area includes an initial injection area and an edge injection area. The initial injection area reaches a preset bonding range in the direction toward the middle area of ​​the packaged chip. The bonding strength and bonding area of ​​the edge injection area meet the preset bonding strength and preset bonding area. The spacing distance between any adjacent target injection areas is greater than a preset distance threshold.

[0050] It should be noted that although the present application is disclosed as above in the form of a preferred embodiment, it is not intended to limit the present application. Any technical personnel in this field may make possible changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined by the claims of the present application.

Claims

1. A chip glue injection method, characterized in that: The method comprises: After welding the packaged chip with solder balls evenly arranged on the bottom to the circuit substrate, the packaged chip is subjected to a first preheating treatment, a first amount of structural adhesive is injected into the corners of the packaged chip, and a high-temperature curing treatment is performed after the first predetermined insulation time to form an initial injection area corresponding to each of the corners, and the first amount of structural adhesive and the first predetermined insulation time enable the initial injection area to reach a preset bonding range in the direction toward the middle area of ​​the packaged chip; Performing a second preheating treatment on the packaged chip, injecting a second amount of structural adhesive into the corners of the packaged chip, and performing a high-temperature curing treatment after keeping the temperature for a second predetermined time, so as to form an edge injection area corresponding to each of the corners, and the second amount of structural adhesive and the second predetermined insulation time make the bonding strength and bonding area of ​​the edge injection area meet the preset bonding strength and preset bonding area; The initial glue injection area and the edge glue injection area form a target glue injection area, and the interval distance between any adjacent target glue injection areas is not less than a predetermined distance threshold.

2. The chip glue injection method according to claim 1, characterized in that: The initial glue injection area is connected to the edge glue injection area.

3. The chip glue injection method according to claim 1, characterized in that: Injecting a first amount of structural adhesive into the corners of the packaged chip, comprising: injecting 90±10㎎ of structural adhesive into the corners of the packaged chip using an L-shaped adhesive injection method, wherein, for each of the corners, the length of the starting adhesive injection edge of the same end angle is less than the length of the ending adhesive injection edge, so that the amount of structural adhesive injected toward the center area of ​​the starting adhesive injection edge and the ending adhesive injection edge is the same.

4. The chip glue injection method according to claim 3, characterized in that: The length of the starting glue injection edge is 10 mm to 11 mm, and the length of the ending glue injection edge is 12 mm to 13 mm.

5. The chip glue injection method according to claim 1, characterized in that: Injecting a second amount of structural adhesive into the corners of the packaged chip comprises: injecting 6±2㎎ of structural adhesive into the corners of the packaged chip using an L-shaped adhesive injection method, wherein the lengths of two adhesive injection edges at the same end corner are 3㎜ to 5㎜.

6. The chip glue injection method according to claim 1, characterized in that: The first predetermined insulation time includes insulation for 3±1 minutes, or the second predetermined insulation time includes insulation for 3±1 minutes.

7. The chip glue injection method according to claim 1, characterized in that: The first preheating treatment of the packaged chip includes: preheating the packaged chip to 80° C. to 90° C.; or, The performing a second preheating treatment on the packaged chip includes: preheating the packaged chip to 80° C. to 90° C.

8. The chip glue injection method according to claim 1, characterized in that: The high-temperature curing treatment after the first predetermined heat preservation period includes: after the first predetermined heat preservation period, the initial glue injection area is subjected to high-temperature curing treatment at a temperature of 140° C. to 160° C. for a period of 14 minutes to 18 minutes; or The high temperature curing treatment is performed after the second predetermined heat preservation period, including: after the second predetermined heat preservation period, the edge injection area is subjected to high temperature curing treatment at a temperature of 140° C. to 160° C. for a time of 14 minutes to 18 minutes.

9. The chip glue injection method according to claim 1, characterized in that: Injecting a first amount of structural adhesive into the corners of the packaged chip, comprising: injecting the first amount of structural adhesive into each corner of the packaged chip in a clockwise direction; or, Injecting a second amount of structural adhesive into the corners of the packaged chip includes: injecting the second amount of structural adhesive into each corner of the packaged chip in a clockwise direction.

10. The chip glue injection method according to claim 1, characterized in that: The predetermined distance threshold includes a spacing corresponding to 5 to 20 solder balls.

11. A semiconductor structure, characterized in that: It includes a packaged chip and a circuit substrate, wherein solder balls are evenly arranged on the bottom of the packaged chip, and the packaged chip is welded to the circuit substrate through the solder balls. A target glue injection area formed by injecting structural glue is included between each corner area of ​​the packaged chip and the circuit substrate, and the target glue injection area includes an initial glue injection area and an edge glue injection area. The initial glue injection area reaches a preset bonding range in the direction toward the middle area of ​​the packaged chip, and the bonding strength and bonding area of ​​the edge glue injection area meet the preset bonding strength and preset bonding area, and the spacing distance between any adjacent target glue injection areas is not less than a preset distance threshold.

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