CN114499447A

CN114499447A - Board-level framework, manufacturing method thereof, system-level packaging structure and electronic equipment

Info

Publication number: CN114499447A
Application number: CN202111578166.8A
Authority: CN
Inventors: 李景明; 尚攀举; 佘勇; 孙亮权
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-12-22
Filing date: 2021-12-22
Publication date: 2022-05-13

Abstract

The application provides a board-level architecture, a manufacturing method thereof, a system-level packaging structure and an electronic device, wherein the board-level architecture can comprise: a circuit board, and at least one filter chip and at least one sealing structure located over the circuit board; the filter chip is provided with an electrode structure on a first surface, and the first surface is the surface of the filter chip facing to one side of the circuit board; each sealing structure wraps the filter chip; the sealing structure is contacted with the side wall of the corresponding filter chip, the sealing structure is contacted with the surface of the circuit board, and the sealing structure is not contacted with the first surface of the corresponding filter chip; the sealing structure, the first surface of the corresponding filter chip and the circuit board form a cavity, and the projection area of the cavity on the circuit board is larger than that of the corresponding filter chip on the circuit board. Therefore, the sealing structure can be ensured not to pollute the first surface of the filter chip, and the performance of the filter chip is improved so as to meet the requirements of electronic equipment.

Description

Board-level framework, manufacturing method thereof, system-level packaging structure and electronic equipment

Technical Field

The present disclosure relates to the field of chip packaging technologies, and in particular, to a board level architecture, a manufacturing method thereof, a system level package structure, and an electronic device.

Background

With the continuous development of electronic technology, electronic devices such as smart phones, smart watches, and personal digital assistants are gradually developing in the directions of being light, thin, compact, and high-performance, and as a key component of communication devices, filters are gradually developing in the directions of being high-frequency and compact. Among them, Surface Acoustic Wave (SAW) filters are widely used in various electronic devices.

Although the surface acoustic wave filter has advantages of small size, low loss, good frequency selectivity, etc. compared with the conventional dielectric filter, the surface acoustic wave filter in the related art has poor performance and is difficult to meet the requirements of electronic devices.

Disclosure of Invention

The embodiment of the application provides a board-level architecture, a manufacturing method thereof, a system-level packaging structure and electronic equipment, and aims to solve the problem that a surface acoustic wave filter in the related art is poor in performance.

In a first aspect, an embodiment of the present application provides a board-level architecture, where the board-level architecture may include: the circuit board, and at least one filter chip and at least one seal structure located over the circuit board. The filter chip is provided with an electrode structure on a first surface, and the first surface is the surface of the filter chip facing to one side of the circuit board. Each sealing structure wraps the filter chip, the sealing structure is in contact with the side wall of the corresponding filter chip, the sealing structure is in contact with the surface of the circuit board, and the sealing structure is not in contact with the first surface of the corresponding filter chip. The sealing structure, the first surface of the corresponding filter chip and the circuit board form a cavity, the projection area of the cavity on the circuit board is larger than that of the corresponding filter chip on the circuit board, and the projection area is in the thickness direction of the circuit board. It is understood that, in the embodiments of the present application, the filter chip corresponding to the sealing structure refers to: the filter chip wrapped by the sealing structure and corresponding to the cavity refers to: and the filter chip is wrapped by the sealing structure forming the cavity.

In the board-level architecture provided by the embodiment of the application, the filter chip can be a surface acoustic wave filter chip or a bulk acoustic wave filter chip. Through setting up the seal structure of parcel filter chip, seal structure, the first surface and the circuit board of the filter chip that corresponds constitute the cavity. The cavity is beneficial to the transmission of sound waves, and the filtering effect of the filter chip can be improved. And, seal structure and the lateral wall contact of the filter chip that corresponds, seal structure and the surface contact of circuit board, and seal structure and the first surface of the filter chip that corresponds are not mutually contacted, the projected area of cavity on the circuit board is greater than the projected area of the filter chip that corresponds on the circuit board, can make the space of cavity great, thereby, guarantee that seal structure can not pollute the first surface of filter chip, avoid seal structure to influence the function of filter chip, promote the performance of filter chip, make the filter chip can satisfy electronic equipment's demand.

In addition, in the embodiment of the application, because the sealing structure does not pollute the first surface of the filter chip, when the structure of the filter chip is designed, parts such as an electrode structure and the like can be arranged at a position close to the edge of the filter chip, so that the wiring area is increased, and the wiring design is facilitated. In the manufacturing process of the board-level framework, the filter chip can be attached to the surface of the circuit board, and the sealing structure is formed around the filter chip, so that the first surface of the filter chip can be prevented from being polluted by structures such as a subsequently formed plastic packaging layer and the like, the yield of the board-level framework is improved, the complexity and the integration difficulty of the manufacturing process are low, and the manufacturing cost is saved.

In this embodiment, the filter chip may be a surface acoustic wave filter chip, and the filter chip is provided with an electrode structure on the first surface, where the electrode structure may be an interdigital comb electrode. The filter chip may be provided with two electrode structures on the first surface, wherein one of the electrode structures may serve as a transmitting transducer and the other electrode structure may serve as a receiving transducer. In the working process of the filter chip, the transmitting transducer converts radio-frequency signals into surface acoustic waves, the surface acoustic waves are transmitted in a cavity on the circuit board, and after the surface acoustic waves are transmitted to the receiving transducer, the receiving transducer converts the surface acoustic waves into electric signals to be output. In the embodiment of the application, the sealing structure, the first surface of the corresponding filter chip and the circuit board form a cavity, so that the surface acoustic wave can be transmitted in the cavity, the transmission efficiency of the surface acoustic wave is improved, and the filtering effect of the filter chip is improved.

In this embodiment, the filter chip may also be a bulk acoustic wave filter chip, the filter chip is provided with an electrode structure on a first surface, and the filter chip is also provided with an electrode structure on a second surface, where the second surface is a surface of the filter chip away from the circuit board. The electrode structures on the first surface and the second surface of the filter chip can excite sound waves, the sound waves are transmitted in the direction perpendicular to the first surface of the filter chip, a cavity is formed by the first surface of the filter chip corresponding to the sealing structure and the circuit board, the cavity can improve the transmission efficiency of the sound waves, the cavity can filter the sound waves, and the filtering effect of the filter chip is improved.

Alternatively, in the embodiment of the present application, the Circuit Board may be a glass substrate, a lead frame (leadframe) substrate, a carrier, a Printed Circuit Board (PCB), a Printed Wiring Board (PWB) main Board (main Board), a package substrate, or the like, a metal wiring layer, a pad, and other components may be disposed on a surface of the Circuit Board, and at least one pad on the Circuit Board is grounded. The filter chip can be electrically connected with the bonding pads on the surface of the circuit board through the solder balls, so that the filter chip is electrically connected with the metal circuit layer on the surface of the circuit board.

In a possible implementation manner, the filter chip may further include a connection portion on the first surface, and the solder ball is electrically connected to the connection portion, so that the solder ball may be fixed to the surface of the filter chip through the connection portion. In the embodiment of the present application, since the sealing structure does not contaminate the first surface of the filter chip, the wiring area of the filter chip is large, and therefore, when the structure of the filter chip is designed, the connection portion may be disposed at any position of the first surface of the filter chip, for example, the connection portion may be disposed at a position having a certain distance from the edge of the filter chip. Alternatively, the connection portion may be provided at a position close to the edge of the filter chip.

In a specific implementation, the filter chip may further include an organic film layer on the first surface. The first surface, the connecting part and the organic film layer of the filter chip can form a cavity, so that the transmission efficiency of sound waves can be further improved, and the filtering effect of the filter chip is improved. In addition, the organic film layer can protect the electrode structure and prevent the electrode structure from being damaged by the subsequent process. Of course, the filter chip in the embodiment of the present application may not be provided with an organic film layer, which is not limited herein.

In some embodiments of the present application, in a direction in which the circuit board points to the filter chip, a cross-sectional area of the cavity in a direction parallel to the circuit board tends to increase first and then decrease or gradually decrease. Therefore, the space of the cavity can be larger, the distance between the partial sealing structure around the cavity and the first surface of the filter chip is longer, and the sealing structure is ensured not to be contacted with the first surface of the filter chip, so that the sealing structure is prevented from being contacted with the electrode structure of the filter chip.

In one possible implementation, the sealing structure may include: the filter comprises a dam which is positioned above the circuit board and surrounds the corresponding filter chip, and a filling part which is positioned on one side of the dam, which faces away from the circuit board. The box dam surrounds corresponding filter chip, and the box dam is cyclic annular promptly, can make to have certain interval between the partial seal structure that is close to the circuit board and the filter chip that corresponds, guarantees that seal structure and the first surface of the filter chip that corresponds do not contact each other. The filling part is connected with the box dam, and the filling part fills the gap between the box dam and the corresponding filter chip, so that the sealing structure can be in close contact with the side wall of the corresponding filter chip, and the sealing structure, the corresponding filter chip and the circuit board form a cavity.

In the manufacturing process, an ink jet printing process may be used to form a dam surrounding the filter chip on the circuit board, and then, the dam may be printed toward the filter chip at a step value, which may be about 10 μm, to form a filling portion filling a gap between the dam and the corresponding filter chip. In practical applications, the height of the dam may be greater than the distance between the first surface of the filter chip and the surface of the circuit board, and less than the distance between the second surface of the filter chip and the surface of the circuit board. For example, the height of the dam may be set to be greater than the distance between the first surface of the filter chip and the surface of the circuit board by 20 μm or more. Of course, the height of the dam may be equal to or less than the distance between the first surface of the filter chip and the surface of the circuit board, which is not limited herein. Alternatively, the width of the dam may be set to be between 80 μm and 100 μm, and the distance between the dam and the edge of the filter chip may be set to be between 10 μm and 30 μm. In the embodiment of the present application, an ink jet printing process is used for manufacturing the box dam and the filling portion as an example, and in specific implementation, other processes may also be used for manufacturing the box dam and the filling portion, which is not limited herein.

Further, the seal structure may further include: and a top cover connected with the filling part. The top cover at least covers the edge of the second surface of the corresponding filter chip, and the second surface is the surface of one side of the filter chip, which is far away from the circuit board. Therefore, the tightness between the sealing structure and the filter chip can be further improved, and the sealing effect of the sealing structure is improved. Alternatively, the thickness of the top cover may be set to be between 20 μm and 30 μm.

In a possible implementation, can set up the top cap into the second surface that covers the filter chip completely, on the one hand, can improve the inseparable degree between seal structure and the filter chip further, promote seal structure's sealed effect, and on the other hand, the top cap also can play the guard action to the filter chip, prevents that follow-up technology from causing the damage to the filter chip. In some embodiments of the present application, the top cover may also cover only an edge portion of the filter chip, so that the tightness between the sealing structure and the filter chip may also be higher, and the sealing effect of the sealing structure may be better. Of course, in other embodiments of the present application, the top cover may not be disposed in the sealing structure, and the sealing structure may be disposed according to actual needs, which is not limited herein.

It should be noted that, for clearly explaining the structure and the manufacturing process of the sealing structure, in the embodiment of the present application, the sealing structure includes the box dam and the filling portion, or the sealing structure includes the box dam, the filling portion and the top cover as an example for explanation, in practical application, each part in the sealing structure may be an integrated structure, and certainly, under the condition that the connection of each part in the sealing structure is ensured to be firm, each part in the sealing structure may also be separately arranged, which is not limited herein.

In an embodiment of the application, each sealing structure encloses at least one filter chip. That is, each sealing structure may wrap one filter chip, or each sealing structure may wrap two, three, or more filter chips adjacently disposed, which is not limited herein.

In a possible implementation manner, at least two adjacent filter chips are arranged on the circuit board, and the sealing structures corresponding to the at least two adjacent filter chips are of an integral structure. Two seal structures corresponding to two adjacent filter chips can share the same side. In specific implementation, in order to facilitate forming a sealing structure between two adjacent filter chips, a gap between the two adjacent filter chips may be set to be greater than 0.1mm, and certainly, in order to make the integration level of the board-level architecture higher, the gap between the two adjacent filter chips is not too large.

In a second aspect, an embodiment of the present application further provides a System In a Package Structure (SIP), where the System In a Package structure may include any one of the board level architectures described above, and a first device, and the first device is located on a circuit board of the board level architecture. In the system architecture, the sealing structure is arranged around the filter chip, the sealing structure, the first surface of the corresponding filter chip and the circuit board can form a cavity, the cavity is favorable for transmission of sound waves, and the filtering effect of the filter chip can be improved. And the sealing structure is not contacted with the first surface of the corresponding filter chip, the projection area of the cavity on the circuit board is larger than that of the corresponding filter chip on the circuit board, so that the space of the cavity is larger, the sealing structure can be ensured not to pollute the first surface of the filter chip, and the performance of the filter chip is improved. Thus, the performance of the system-in-package structure including the board-level architecture is also better.

In practical applications, the first device may be an active device or a passive device, where the active device may be an amplifier, a converter, or the like, and the passive device may be a capacitor, a resistor, a switch, or the like. In specific implementation, the number and the type of the first devices may be set according to actual needs, as long as the first devices can be matched with the filter chip in circuit. The distance between the filter chip and the first device can be set to be less than 100 μm, so that the layout density can be improved, and the high-density layout and miniaturization trend of a system-in-package structure is facilitated.

In practical applications, the system in package structure in the embodiment of the present application may further include: and the plastic packaging layer is positioned on the circuit board and wraps the filter chips, the sealing structures and the first devices on the circuit board. By adopting the plastic package layer to package each filter chip, the packaging stability of each filter chip can be improved. The molding compound may encapsulate the first devices on the circuit board, for example, the molding compound may encapsulate the active devices and the passive devices on the circuit board. Therefore, the filter chip and the first device can be packaged in the same system-in-package structure, the integration level of the system-in-package structure can be effectively improved, the space is saved, and the manufacturing cost is reduced. Moreover, the filter chip and the first device are convenient to carry out circuit adaptation, so that the system-in-package structure is simple in structure, the loss of radio-frequency signals is effectively reduced, and the radio-frequency efficiency is improved.

Optionally, the material of the molding layer may include: an epoxy material, an acrylic material, a dielectric material, a thermoset material, a thermoplastic material, a rubber material, or other insulating material.

In the actual process, the filter chip and the first device are attached to the circuit board, a sealing structure is formed around the filter chip, and then a plastic packaging layer is formed on the circuit board by adopting an injection process. In the injection process, the sealing structure can play a role in preventing the plastic packaging material from contacting the first surface of the filter chip. In addition, the sealing structure can also protect the filter chip, prevent the filter chip from being damaged by mold flow pressure generated by the plastic packaging material, and improve the plastic packaging yield. For example, the dam in the sealing structure may prevent the first surface of the filter chip and the solder balls from being damaged, the filling part in the sealing structure may prevent the sidewall of the filter chip from being damaged, and the cap in the sealing structure may prevent the second surface of the filter chip from being damaged.

In a third aspect, an embodiment of the present application further provides an electronic device, where the electronic device may include: any one of the system-in-package structures and a shell, wherein the shell covers the system-in-package structure. For example, the electronic device may be any radio frequency enabled device such as a smart phone, a smart watch, a personal digital assistant, a base station, and the like. Since the performance of the system-in-package structure is better, the performance of the electronic device including the system-in-package structure is also better.

In a fourth aspect, an embodiment of the present application further provides a manufacturing method of a board level architecture, where the manufacturing method may include:

providing a circuit board and at least one filter chip; the filter chip is provided with an electrode structure on the first surface;

attaching at least one filter chip to the surface of the circuit board in a direction that the first surface faces the circuit board;

forming a sealing structure which is contacted with the side wall of the filter chip, contacted with the surface of the circuit board and not contacted with the first surface of the filter chip at the periphery of at least one filter chip so as to enable the sealing structure, the first surface of the corresponding filter chip and the circuit board to form a cavity; each sealing structure wraps the filter chip, the projection area of the cavity on the circuit board is larger than that of the corresponding filter chip on the circuit board, and the projection area is in the thickness direction of the circuit board.

In the manufacturing method of the board-level architecture provided by the embodiment of the application, the filter chip is attached to the surface of the circuit board, the sealing structure which is in contact with the side wall of the filter chip and in contact with the surface of the circuit board and is not in contact with the first surface of the filter chip is formed around at least one filter chip, and thus, the first surface of the filter chip can be prevented from being polluted by structures such as a plastic packaging layer formed subsequently, the sealing structure is prevented from influencing the function of the filter chip, the performance of the filter chip is improved, the yield of the board-level architecture is improved, the complexity and the integration difficulty of the manufacturing process are low, and the manufacturing cost is saved.

And the sealing structure, the first surface of the corresponding filter chip and the circuit board form a cavity, and the cavity is favorable for the transmission of sound waves and can improve the filtering effect of the filter chip. In addition, the projection area of the cavity on the circuit board is larger than that of the corresponding filter chip on the circuit board, so that the space of the cavity is larger, the first surface of the filter chip can not be polluted by the sealing structure, the influence of the sealing structure on the function of the filter chip is avoided, the performance of the filter chip is improved, and the filter chip can meet the requirement of electronic equipment.

In a possible implementation manner, the Circuit Board may be a glass Circuit Board, a lead frame (leadframe) Circuit Board, a carrier, a Printed Circuit Board (PCB), a Printed Wiring Board (PWB) main Board (main Board), a package substrate, or the like, a metal Circuit layer, a pad, and other components may be disposed on a surface of the Circuit Board, and at least one pad on the Circuit Board is grounded. The filter chip may be a surface acoustic wave filter chip or a bulk acoustic wave filter chip. The surface acoustic wave filter chip can be provided with two electrode structures on the first surface, wherein one electrode structure can be used as a transmitting transducer, and the other electrode structure can be used as a receiving transducer. The bulk acoustic wave filter chip is provided with an electrode structure on a first surface, and the filter chip is also provided with an electrode structure on a second surface.

In one possible implementation, the filter chip is attached to a surface of the circuit board, and the first surface of the filter chip faces the circuit board. The filter chip is electrically connected with the bonding pad on the surface of the circuit board through the solder ball, so that the filter chip is electrically connected with the metal circuit layer on the surface of the circuit board.

In the manufacturing method provided by the embodiment of the application, the sealing structure can be manufactured in the following manner:

a dam is formed around the filter chip, which can be made, for example, by an inkjet printing process. The height of the box dam can be smaller than the distance between the second surface of the filter chip and the surface of the circuit board, and the second surface is the surface of the filter chip, which is far away from the circuit board. In practical applications, the height of the dam may be larger than the distance between the first surface of the filter chip and the surface of the circuit board. For example, the height of the dam may be set to be greater than the distance between the first surface of the filter chip and the surface of the circuit board by 20 μm or more. Of course, the height of the dam may be equal to or less than the distance between the first surface of the filter chip and the surface of the circuit board, which is not limited herein. Alternatively, the width of the dam may be set to be between 80 μm and 100 μm, and the distance between the dam and the edge of the filter chip may be set to be between 10 μm and 30 μm.

Some process errors are allowed during the process of making the dam, for example, the material of the dam may flow to a position under the filter chip on the surface of the circuit board, or may be in contact with the solder balls under the filter chip, as long as it is ensured that the material of the dam does not contact the first surface of the filter chip. Therefore, the process window can be enlarged, and the process difficulty is reduced.

Then, a filling portion that fills a gap between the dam and the filter chip and is in contact with the side wall of the filter chip is formed above the dam, and the dam and the corresponding filling portion may constitute the above-described sealing structure. In an actual process, an inkjet printing process may be used to print on the dam toward the filter chip at a certain step value, so as to form a filling portion filling a gap between the dam and the corresponding filter chip, where the step value may be about 10 μm, for example.

In one possible implementation, after forming the filling portion, the method may further include:

a top cover connected with the filling part is formed on the second surface of the filter chip. In the actual process, the top cover can be manufactured by adopting an ink-jet printing process. Through forming the top cap of being connected with the packing portion, can further improve the inseparable degree between seal structure and the filter chip, promote seal structure's sealed effect. Alternatively, the thickness of the top cover may be set to be between 20 μm and 30 μm.

Wherein the top cover covers at least an edge of the second surface of the filter chip. The top cover may completely cover the second surface of the filter chip; or, the top cover may also cover only the edge portion of the filter chip, and of course, in other embodiments of the present application, the top cover may not be provided in the sealing structure, and may be provided according to actual needs, which is not limited herein.

In the embodiment of the present application, the dam, the filling portion, and the top cover are manufactured by using an inkjet printing process as an example, and in the specific implementation, the dam, the filling portion, and the top cover may also be manufactured by using other processes, which is not limited herein.

In the embodiment of the present application, a manufacturing method of the system-in-package structure is similar to the manufacturing method of the board-level architecture, and the difference is that: in the manufacturing process of the system-in-package structure, before a sealing structure for wrapping the filter chip is formed, a first device is required to be attached to the circuit board, and the first device can be an active device or a passive device; and after the sealing structure is formed, a plastic packaging layer which wraps the filter chips, the sealing structures and the first devices on the circuit board is formed. The process of forming the sealing structure by the system-in-package structure is similar to the process of forming the sealing structure in the board-in-package structure, and repeated details are omitted.

In an embodiment of the present application, a method for manufacturing a system in package structure may include:

and attaching the filter chip and the first device to the surface of the circuit board. The first device may be an active device or a passive device. The active device may be an amplifier, a converter, or other devices, and the passive device may be a capacitor, a resistor, or other devices. In specific implementation, the number and the type of the first devices may be set according to actual needs, as long as the first devices can be matched with the filter chip in circuit. The distance between the filter chip and the first device can be set to be less than 100 μm, so that the layout density can be improved, and the high-density layout and miniaturization trend of a system-in-package structure is facilitated.

A dam surrounding the filter chip is formed, and a filling portion filling a gap between the dam and the filter chip and contacting a sidewall of the filter chip is formed over the dam. After the filling part is formed, a top cover connected to the filling part may be further formed on the second surface of the filter chip. Some process errors are allowed during the process of making the dam, for example, the material of the dam may flow to a position under the filter chip on the surface of the circuit board, or may be in contact with the solder balls under the filter chip, as long as it is ensured that the material of the dam does not contact the first surface of the filter chip. Therefore, the process window can be enlarged, and the process difficulty is reduced. In addition, the material of box dam also can flow to the below of adjacent first device, through filling the clearance between first device and the circuit board, can realize the function of primer (underfill), promotes the reliability of first device.

After the sealing structure is formed, a molding layer is formed to wrap each filter chip, each sealing structure, and each first device on the circuit board, for example, the first devices may be active devices and passive devices. By adopting the plastic package layer to package each filter chip, the packaging stability of each filter chip can be improved. In the embodiment of the application, the filter chip and the first device are packaged in the same system-in-package structure, so that the integration level of the system-in-package structure can be effectively improved, the space is saved, and the manufacturing cost is reduced. Moreover, the filter chip and the first device are convenient to carry out circuit adaptation, so that the system-in-package structure is simple in structure, the loss of radio-frequency signals is effectively reduced, and the radio-frequency efficiency is improved.

In the actual process, an injection process may be used to form a molding layer on the circuit board. In the injection process, the sealing structure can play a role in preventing the plastic packaging material from contacting the first surface of the filter chip. In addition, the sealing structure can also protect the filter chip, prevent the filter chip from being damaged by mold flow pressure generated by the plastic packaging material, and improve the plastic packaging yield. For example, the dam in the sealing structure may prevent the first surface of the filter chip and the solder balls from being damaged, the filling part in the sealing structure may prevent the sidewall of the filter chip from being damaged, and the cap in the sealing structure may prevent the second surface of the filter chip from being damaged.

Drawings

Fig. 1 is a schematic structural diagram of a board-level architecture according to an embodiment of the present disclosure;

fig. 2 is a schematic plan view of a saw filter chip according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a bulk acoustic wave filter chip according to an embodiment of the present application;

fig. 4 is another schematic structural diagram of a board-level architecture according to an embodiment of the present disclosure;

fig. 5 is another schematic structural diagram of a board-level architecture according to an embodiment of the present disclosure;

fig. 6 is another schematic structural diagram of a board-level architecture according to an embodiment of the present disclosure;

fig. 7 is another schematic structural diagram of a board-level architecture according to an embodiment of the present disclosure;

fig. 8 is another schematic structural diagram of a board-level architecture according to an embodiment of the present disclosure;

fig. 9 is another schematic structural diagram of a board-level architecture according to an embodiment of the present application;

fig. 10 is another structural diagram of a board-level architecture according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of a system in package structure according to an embodiment of the present application;

fig. 12 is a flowchart of a method for manufacturing a board level architecture according to an embodiment of the present disclosure;

fig. 13 to 16 are schematic structural diagrams corresponding to steps in a method for manufacturing a board level architecture according to an embodiment of the present application;

fig. 17 to fig. 20 are schematic structural diagrams corresponding to steps in a method for manufacturing a system in package structure in an embodiment of the present application.

Reference numerals are as follows:

100-board level architecture; 10-a circuit board; 11-a filter chip; 111-electrode structure; 112-a connecting portion; 113-an organic film layer; 12-a sealing structure; 121-box dam; 122-a filling section; 123-a top cover; 13-solder balls; 14-an active device; 15-passive devices; 16-plastic packaging layer; s1 — first surface; s2 — a second surface; q-cavity; w-cavity.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more clear, the present application will be further described in detail with reference to the accompanying drawings.

It should be noted that the same reference numerals in the drawings of the present application denote the same or similar structures, and thus, a repetitive description thereof will be omitted. The words used in this application to describe positions and orientations are provided by way of example in the drawings, but can be modified as required and are intended to be encompassed by the present application. The drawings of the present application are for illustrating relative positional relationships only and do not represent true scale.

In order to solve the problem of poor performance of a surface acoustic wave filter in the related art, the embodiment of the application provides a board-level architecture, a manufacturing method thereof, a system-level packaging structure and an electronic device. The board-level architecture may be used to package a surface acoustic wave (saw) filter chip or a Bulk Acoustic Wave (BAW) filter chip, and of course, the board-level architecture may also be used to package other types of chips, which is not limited herein. The system-in-package structure in the embodiment of the present application may be applied to various types of electronic devices, for example, the electronic device may be any device with a radio frequency function, such as a smart phone, a smart watch, a personal digital assistant, and a base station.

Fig. 1 is a schematic structural diagram of a board-level architecture provided in the embodiment of the present application, and as shown in fig. 1, the board-level architecture provided in the embodiment of the present application may include: a circuit board 10, and at least one filter chip 11 and at least one sealing structure 12 located on the circuit board 10. The filter chip 11 is provided with an electrode structure (not shown in fig. 1) at a first surface S1, the first surface S1 being the surface of the filter chip 11 facing the circuit board 10 side. Each sealing structure 12 wraps the filter chip 11, the sealing structure 12 contacts with the side wall of the corresponding filter chip 11, the sealing structure 12 contacts with the surface of the circuit board 10, and the sealing structure 12 does not contact with the first surface S1 of the corresponding filter chip 11. The sealing structure 12, the first surface S1 of the corresponding filter chip 11, and the circuit board 10 constitute a cavity Q, and a projected area of the cavity Q on the circuit board 10 is larger than a projected area of the corresponding filter chip 11 on the circuit board 10, which is a projected area in the thickness direction of the circuit board 10. It is understood that, in the embodiment of the present application, the filter chip 11 corresponding to the sealing structure 12 refers to: the filter chip 11 wrapped by the sealing structure 12, the filter chip 11 corresponding to the cavity Q means: and a sealing structure 12 forming the cavity Q, and a filter chip 11 wrapped by the sealing structure.

Fig. 2 is a schematic plan view of a surface acoustic wave filter chip in an embodiment of the present invention, and with reference to fig. 1 and fig. 2, in the embodiment of the present invention, the filter chip 11 may be a surface acoustic wave filter chip, and the filter chip 11 is provided with an electrode structure 111 on the first surface S1, where the electrode structure 111 may be an interdigital comb electrode. The filter chip 11 may be provided with two electrode structures 111 at the first surface S1, wherein one electrode structure 111 may be used as a transmitting transducer and the other electrode structure 111 may be used as a receiving transducer. In the working process of the filter chip 11, the transmitting transducer converts radio frequency signals into surface acoustic waves, the surface acoustic waves are transmitted in the cavity Q above the circuit board 10, and after the surface acoustic waves are transmitted to the receiving transducer, the receiving transducer converts the surface acoustic waves into electric signals to be output. In the embodiment of the present application, the sealing structure 12, the corresponding first surface S1 of the filter chip 11 and the circuit board 10 form the cavity Q, so that the surface acoustic wave can be transmitted in the cavity Q, the transmission efficiency of the surface acoustic wave is improved, and the filtering effect of the filter chip 11 is improved.

Fig. 3 is a schematic structural diagram of a bulk acoustic wave filter chip in an embodiment of the present invention, and with reference to fig. 1 and fig. 3, in the embodiment of the present invention, the filter chip 11 may also be a bulk acoustic wave filter chip, the filter chip 11 is provided with an electrode structure 111 on a first surface S1, and the filter chip 11 is also provided with an electrode structure 111 on a second surface S2, where the second surface S2 is a surface of the filter chip 11 on a side away from the circuit board 10. Since the electrode structures 111 in the second surface S2 are not visible at the viewing angle shown in fig. 3, the electrode structures 111 in the second surface S2 are indicated by dotted lines. The electrode structures 111 on the first surface S1 and the second surface S2 of the filter chip 11 can excite acoustic waves, the acoustic waves propagate in a direction perpendicular to the first surface S1 of the filter chip 11, and a cavity Q is formed by the sealing structure 12, the corresponding first surface S1 of the filter chip 11 and the circuit board 10, the cavity Q can improve the transmission efficiency of the acoustic waves, and the cavity Q can filter the acoustic waves, so that the filtering effect of the filter chip 11 is improved.

Alternatively, in the embodiment of the present application, the Circuit Board may be a glass Circuit Board, a lead frame (lead frame) Circuit Board, a carrier Board, a Printed Circuit Board (PCB), a Printed Wiring Board (PWB) main Board (main Board), a package substrate, or the like, a metal wiring layer, a pad, and other components may be disposed on a surface of the Circuit Board, and at least one pad on the Circuit Board is grounded. Referring to fig. 1, the filter chip 11 may be electrically connected to pads on the surface of the circuit board 10 through solder balls 13, so that the filter chip 11 is electrically connected to a metal wiring layer on the surface of the circuit board 10.

Fig. 4 is another schematic structural diagram of the board-level architecture according to the embodiment of the present disclosure, as shown in fig. 4, the filter chip 11 may further include a connection portion 112 on the first surface S1, and the solder ball 13 is electrically connected to the connection portion 112, so that the solder ball 13 may be fixed to the surface of the filter chip 11 through the connection portion 112. In the embodiment of the present application, since the sealing structure 12 does not contaminate the first surface S1 of the filter chip 11, so that the wiring area of the filter chip is large, when designing the structure of the filter chip, the connection portion 112 may be disposed at any position of the first surface S1 of the filter chip 11, for example, the connection portion 112 may be disposed at a position having a certain distance from the edge of the filter chip 11. Fig. 5 is another schematic structural diagram of the board-level architecture provided in the embodiment of the present application, and as shown in fig. 5, in the embodiment of the present application, the connection portion 112 may also be disposed at a position closer to the edge of the filter chip 11.

Fig. 6 is another structural schematic diagram of the board-level structure in the embodiment of the present application, and as shown in fig. 6, the filter chip 11 may further be provided with an organic film layer 113 on the first surface S1 side. The first surface S1 of the filter chip 11, the connection portion 112 and the organic film 113 may form a cavity W, so that the transmission efficiency of the sound wave may be further improved, and the filtering effect of the filter chip 11 may be improved. In addition, the organic film 113 can protect the electrode structure 111, and prevent the electrode structure 111 from being damaged by a subsequent process. Of course, the filter chip 11 in the embodiment of the present application may not be provided with the organic film layer 113, and is not limited herein.

In some embodiments of the present application, as shown in fig. 1, in a direction in which the circuit board 10 points to the filter chip 11 (i.e., a direction from bottom to top in the drawing), a cross-sectional area of the cavity Q in a direction parallel to the circuit board 10 tends to increase first and then decrease. Fig. 7 is another structural schematic diagram of the board-level architecture according to the embodiment of the present disclosure, as shown in fig. 7, in a direction in which the circuit board 10 points to the filter chip 11 (i.e., a direction pointing from bottom to top in the figure), a cross-sectional area of the cavity Q in a direction parallel to the circuit board 10 may also gradually decrease. Thus, the space of the cavity Q can be made larger, the distance between the part of the sealing structure 12 around the cavity Q and the first surface S1 of the filter chip 11 is made longer, and the sealing structure 12 and the first surface S1 of the filter chip 11 are ensured not to be in contact with each other, thereby preventing the sealing structure 12 from being in contact with the electrode structure of the filter chip 11.

In particular implementation, as shown in fig. 1, the sealing structure 12 may include: a dam 121 located above the circuit board 10 and surrounding the corresponding filter chip 11, and a filling portion 122 located on a side of the dam 121 facing away from the circuit board 10. The dam 121 surrounds the corresponding filter chip 11, that is, the dam 121 is annular, so that a certain distance is provided between a part of the sealing structure 12 close to the circuit board 10 and the corresponding filter chip 11, and the sealing structure 12 and the first surface S1 of the corresponding filter chip 11 are ensured not to contact each other. The filling portion 122 is connected to the dam 121, and the filling portion 122 fills the gap between the dam 121 and the corresponding filter chip 11, so that the sealing structure 12 can be brought into close contact with the side wall of the corresponding filter chip 11, and the sealing structure 12, the corresponding filter chip 11, and the circuit board 10 form a cavity Q.

In the manufacturing process, an ink jet printing process may be used to form a dam 121 surrounding the filter chip 11 on the circuit board 10, and then, printing may be performed on the dam 121 toward the filter chip 11 at a step value, which may be, for example, about 10 μm, to form the filling portion 122 filling the gap between the dam 121 and the corresponding filter chip 11. In practical applications, the height of the dam 121 may be greater than the distance between the first surface S1 of the filter chip 11 and the surface of the circuit board 10 and less than the distance between the second surface S2 of the filter chip 11 and the surface of the circuit board 10. For example, the height of the dam 121 may be set to be greater than or equal to 20 μm than the distance between the first surface S1 of the filter chip 11 and the surface of the circuit board 10. Of course, the height of the dam 121 may be equal to or less than the distance between the first surface S1 of the filter chip 11 and the surface of the circuit board 10, which is not limited herein. Alternatively, the width of the dam 121 may be set to be between 80 μm and 100 μm, and the distance between the dam 121 and the edge of the filter chip 11 may be set to be between 10 μm and 30 μm. In the embodiment of the present application, the dam 121 and the filling portion 122 are manufactured by using an inkjet printing process as an example, and in the specific implementation, the dam 121 and the filling portion 122 may be manufactured by using other processes, which is not limited herein.

Further, with continued reference to fig. 1, the sealing structure 12 may further include: and a top cover 123 connected to the filling part 122, the top cover 123 covering at least an edge of the second surface S2 of the corresponding filter chip 11, and the second surface S2 is a surface of the filter chip 11 on a side away from the circuit board 10. Thus, the tightness between the sealing structure 12 and the filter chip 11 can be further improved, and the sealing effect of the sealing structure 12 can be improved. Alternatively, the thickness of the top cap 123 may be set to be between 20 μm and 30 μm.

As shown in fig. 1, the top cover 123 may be configured to completely cover the second surface S2 of the filter chip 11, on one hand, the tightness between the sealing structure 12 and the filter chip 11 may be further improved, and the sealing effect of the sealing structure 12 may be improved, and on the other hand, the top cover 123 may also protect the filter chip 11, and prevent the filter chip 11 from being damaged by the subsequent processes. Fig. 8 is another schematic structural diagram of the board-level architecture provided in the embodiment of the present application, as shown in fig. 8, in some embodiments of the present application, the top cover 123 may also cover only an edge portion of the filter chip 11, so that the tightness between the sealing structure 12 and the filter chip 11 may also be higher, and the sealing effect of the sealing structure 12 is better. Of course, in other embodiments of the present application, the top cover 123 may not be disposed in the sealing structure 12, and may be disposed according to actual needs, which is not limited herein.

It should be noted that, for clearly explaining the structure and the manufacturing process of the sealing structure, in the embodiment of the present application, the sealing structure includes the dam and the filling portion, or the sealing structure includes the dam, the filling portion and the top cover as an example for explanation, in practical application, each portion in the sealing structure may be an integrated structure, and certainly, under the condition that the connection of each portion in the sealing structure is ensured to be firm, each portion in the sealing structure may also be separately arranged, and the description is not limited herein.

In the embodiment of the present application, each sealing structure encloses at least one filter chip, and fig. 1 illustrates an example in which each sealing structure 12 encloses one filter chip 11. Fig. 9 is another structural schematic diagram of the board-level architecture provided in the embodiment of the present application, and as shown in fig. 9, each sealing structure 12 may also wrap two adjacent filter chips 11, and of course, each sealing structure may also wrap three or more adjacent filter chips, which is not limited herein.

Fig. 10 is another schematic structural diagram of a board-level architecture according to an embodiment of the present disclosure, as shown in fig. 10, at least two adjacent filter chips 11 are disposed on a circuit board 10, and in fig. 10, taking the example that two adjacent filter chips 11 are disposed on the circuit board 10, sealing structures 12 corresponding to the at least two adjacent filter chips 11 are an integral structure. Two sealing structures 12 corresponding to two adjacent filter chips 11 may share the same side. In specific implementation, in order to facilitate forming the sealing structure 12 between two adjacent filter chips 11, a gap between two adjacent filter chips 11 may be set to be greater than 0.1mm, and certainly, in order to make the integration degree of the board-level architecture higher, the gap between two adjacent filter chips 11 is not too large.

Based on the same technical concept, an embodiment of the present application further provides a System In a Package Structure (SIP), and fig. 11 is a schematic structural diagram of the System In a Package structure provided In the embodiment of the present application, as shown In fig. 11, the System In a Package structure may include any one of the board level architectures 100 described above, and a first device (for example, as shown by 14 or 15 In fig. 11), where the first device is located on the circuit board 10 of the board level architecture 100.

In the system architecture, the sealing structure is arranged around the filter chip, the sealing structure, the first surface of the corresponding filter chip and the circuit board can form a cavity, the cavity is favorable for transmission of sound waves, and the filtering effect of the filter chip can be improved. And the sealing structure is not contacted with the first surface of the corresponding filter chip, the projection area of the cavity on the circuit board is larger than that of the corresponding filter chip on the circuit board, so that the space of the cavity is larger, the sealing structure can be ensured not to pollute the first surface of the filter chip, and the performance of the filter chip is improved. Thus, the performance of the system-in-package structure including the board-level architecture is also better.

The first device may be an active device 14, as shown in fig. 11, or the first device may be a passive device 15. The active device 14 may be an amplifier, a converter, or the like, and the passive device 15 may be a capacitor, a resistor, a switch, or the like. In specific implementation, the number and the type of the first devices may be set according to actual needs, as long as the first devices can be matched with the filter chip 11. The distance between the filter chip 11 and the first device can be set to be less than 100 μm, which can improve the layout density and is beneficial to the high-density layout and miniaturization trend of the system-in-package structure.

In practical applications, as shown in fig. 11, the system in package structure in the embodiment of the present application may further include: the plastic package layer 16 is located on the circuit board 10, the plastic package layer 16 wraps the filter chips 11, the sealing structures 12 and the first devices on the circuit board 10, and the plastic package layer 16 is used for packaging the filter chips 11, so that the packaging stability of the filter chips 11 can be improved. The molding layer 16 may encapsulate the first devices on the circuit board 10, for example, the molding layer 16 may encapsulate the active devices 14 and the passive devices 15 on the circuit board 10. Therefore, the filter chip 11 and the first device can be packaged in the same system-in-package structure, so that the integration level of the system-in-package structure can be effectively improved, the space can be saved, and the manufacturing cost can be reduced. In addition, the filter chip 11 and the first device are conveniently subjected to circuit adaptation, so that the system-in-package structure is simple in structure, the loss of radio-frequency signals is effectively reduced, and the radio-frequency efficiency is improved.

Alternatively, the material of the molding layer 16 may include: an epoxy material, an acrylic material, a dielectric material, a thermoset material, a thermoplastic material, a rubber material, or other insulating material.

In the actual process, the filter chip 11 and the first device are mounted on the circuit board 10, and the sealing structure 12 is formed around the filter chip 11, and then the molding layer 16 is formed on the circuit board 10 by using an injection process. During the injection process, the sealing structure 12 may function to prevent the molding compound from contacting the first surface S1 of the filter chip 11. In addition, the sealing structure 12 can also protect the filter chip 11, prevent the filter chip 11 from being damaged by mold flow pressure generated by the plastic package material, and improve the plastic package yield. For example, the dam 121 in the sealing structure 12 may prevent the first surface S1 of the filter chip 11 and the solder balls 13 from being damaged, the filling part 122 in the sealing structure 12 may prevent the side wall of the filter chip 11 from being damaged, and the top cover 123 in the sealing structure 12 may prevent the second surface S2 of the filter chip 11 from being damaged.

Based on the same technical concept, an embodiment of the present application further provides an electronic device, which may include: any one of the system-in-package structures and a shell, wherein the shell covers the system-in-package structure. For example, the electronic device may be any radio frequency enabled device such as a smart phone, a smart watch, a personal digital assistant, a base station, and the like. Since the performance of the system-in-package structure is better, the performance of the electronic device including the system-in-package structure is also better.

Based on the same technical concept, an embodiment of the present application further provides a method for manufacturing a board level architecture, fig. 12 is a flowchart of the method for manufacturing the board level architecture provided by the embodiment of the present application, and fig. 13 to 16 are schematic structural diagrams corresponding to steps in the method for manufacturing the board level architecture in the embodiment of the present application. As shown in fig. 12, the manufacturing method provided in the embodiment of the present application may include:

s201, providing a circuit board and at least one filter chip; the filter chip is provided with an electrode structure on the first surface;

s202, attaching at least one filter chip to the surface of the circuit board in a direction that the first surface faces the circuit board;

s203, forming a sealing structure which is in contact with the side wall of the filter chip, is in contact with the surface of the circuit board and is not in contact with the first surface of the filter chip around at least one filter chip, so that the sealing structure, the first surface of the corresponding filter chip and the circuit board form a cavity; each sealing structure wraps the filter chip, the projection area of the cavity on the circuit board is larger than that of the corresponding filter chip on the circuit board, and the projection area is in the thickness direction of the circuit board.

And the sealing structure, the first surface of the corresponding filter chip and the circuit board form a cavity, and the cavity is favorable for transmission of sound waves and can improve the filtering effect of the filter chip. In addition, the projection area of the cavity on the circuit board is larger than that of the corresponding filter chip on the circuit board, so that the space of the cavity is larger, the first surface of the filter chip can not be polluted by the sealing structure, the influence of the sealing structure on the function of the filter chip is avoided, the performance of the filter chip is improved, and the filter chip can meet the requirement of electronic equipment.

In step S201, the Circuit Board may be a glass Circuit Board, a lead frame (lead frame) Circuit Board, a carrier Board, a Printed Circuit Board (PCB), a Printed Wiring Board (PWB) main Board (main Board), a package substrate, or the like, a metal wiring layer, a pad, and other components may be disposed on a surface of the Circuit Board, and at least one pad on the Circuit Board is grounded. The filter chip may be a surface acoustic wave filter chip or a bulk acoustic wave filter chip. The structure of the surface acoustic wave filter chip can be as shown in fig. 2, and the surface acoustic wave filter chip is provided with an electrode structure 111 on the first surface S1, and the electrode structure 111 can be an interdigital comb-like electrode. The saw filter chip may be provided with two electrode structures 111 on the first surface S1, wherein one of the electrode structures 111 may serve as a transmitting transducer and the other electrode structure 111 may serve as a receiving transducer. The structure of the bulk acoustic wave filter chip may be as shown in fig. 3, the bulk acoustic wave filter chip is provided with the electrode structures 111 on the first surface S1, and the filter chip 11 is also provided with the electrode structures 111 on the second surface S2.

In the above step S202, as shown in fig. 13, the filter chip 11 is mounted on the surface of the circuit board 10 with the first surface S1 of the filter chip 11 facing the circuit board 10. The filter chip 11 is electrically connected to pads on the surface of the circuit board 10 through solder balls 13, so that the filter chip 11 is electrically connected to the metal wiring layer on the surface of the circuit board 10.

In step S203, the sealing structure may be manufactured as follows:

as shown in fig. 14, a dam 121 surrounding the filter chip 11 is formed, and the dam 121 may be made by, for example, an inkjet printing process. The height h1 of the dam 121 is smaller than the distance h2 between the second surface S2 of the filter chip 11 and the surface of the circuit board 10, and the second surface S2 is the surface of the filter chip 11 on the side away from the circuit board 10. In practical applications, the height h1 of the dam 121 may be greater than the distance h3 between the first surface S1 of the filter chip 11 and the surface of the circuit board 10. For example, the height h1 of the dam 121 may be set to be greater than or equal to 20 μm greater than the distance h3 between the first surface S1 of the filter chip 11 and the surface of the circuit board 10. Of course, the height h1 of the dam 121 may be equal to or less than the distance h3 between the first surface S1 of the filter chip 11 and the surface of the circuit board 10, which is not limited herein. Alternatively, the width of the dam 121 may be set to be between 80 μm and 100 μm, and the distance between the dam 121 and the edge of the filter chip 11 may be set to be between 10 μm and 30 μm.

Referring to fig. 14, in the process of manufacturing the dam 121, there is allowed a certain process error, for example, the material of the dam 121 may flow to a position under the filter chip 11 on the surface of the circuit board 10, or may contact the solder balls 13 under the filter chip 11, as long as it is ensured that the material of the dam 121 does not contact the first surface S1 of the filter chip 11. Therefore, the process window can be enlarged, and the process difficulty is reduced.

Then, as shown in fig. 15, a filling portion 122 that fills a gap between the dam 121 and the filter chip 11 and is in contact with the side wall of the filter chip 11 is formed above the dam 121, and the dam 121 and the corresponding filling portion 122 may constitute the above-described sealing structure. In an actual process, an inkjet printing process may be used to print on the dam 121 toward the filter chip 11 at a certain step value, for example, the step value may be about 10 μm, and the filling portion 122 filling the gap between the dam 121 and the corresponding filter chip 11 is formed.

As shown in fig. 16, after forming the filling portion in step S203, the method may further include:

a top cover 123 connected to the filling portion 122 is formed on the second surface S2 of the filter chip 11. In actual processing, the top cover 123 may be fabricated using an inkjet printing process. By forming the top cover 123 connected to the filling portion 122, the tightness between the sealing structure 12 and the filter chip 11 can be further improved, and the sealing effect of the sealing structure 12 can be improved. Alternatively, the thickness of the top cap 123 may be set to be between 20 μm and 30 μm.

Wherein the top cover 123 covers at least the edge of the second surface S2 of the filter chip 11. As shown in fig. 16, the top cover 123 may be formed to completely cover the second surface S2 of the filter chip 11, on one hand, the tightness between the sealing structure 12 and the filter chip 11 may be further improved, and the sealing effect of the sealing structure 12 may be improved, and on the other hand, the top cover 123 may also protect the filter chip 11, and prevent the filter chip 11 from being damaged by the subsequent processes. Referring to fig. 8, the top cover 123 may be formed to cover only the edge portion of the filter chip 11, so that the sealing structure 12 and the filter chip 11 may be tightly sealed to each other, and the sealing effect of the sealing structure 12 may be improved. Of course, in other embodiments of the present application, the top cover 123 may not be disposed in the sealing structure 12, and may be disposed according to actual needs, which is not limited herein.

In the embodiment of the present application, the dam 121, the filling portion 122, and the top cover 123 are described as an example, and in the specific implementation, the dam 121, the filling portion 122, and the top cover 123 may be manufactured by other processes, which are not limited herein.

In the embodiment of the present application, a manufacturing method of the system-in-package structure is similar to the manufacturing method of the board-level architecture, and the difference is that: in the manufacturing process of the system-in-package structure, before a sealing structure for wrapping the filter chip is formed, a first device is required to be attached to the circuit board, and the first device can be an active device or a passive device; and after the sealing structure is formed, a plastic packaging layer which wraps the filter chips, the sealing structures and the first devices on the circuit board is formed. The process of forming the sealing structure by the system-in-package structure is similar to the process of forming the sealing structure in the board-in-package structure, and repeated details are omitted. Fig. 17 to 20 are schematic structural diagrams corresponding to steps in a method for manufacturing a system-in-package structure in an embodiment of the present application, and the method for manufacturing the system-in-package structure in the embodiment of the present application is briefly described below with reference to the accompanying drawings.

As shown in fig. 17, the filter chip 11 and the first device (shown as 14 and 15 in fig. 17) are attached to the surface of the circuit board 10. For example, the first device may be an active device 14, or alternatively, the first device may be a passive device 15. The active device 14 may be an amplifier, a converter, or the like, and the passive device 15 may be a capacitor, a resistor, or the like. In specific implementation, the number and the type of the first devices may be set according to actual needs, as long as the first devices can be matched with the filter chip 11. The distance between the filter chip 11 and the first device can be set to be less than 100 μm, which can improve the layout density and is beneficial to the high-density layout and miniaturization trend of the system-in-package structure.

As shown in fig. 18, a dam 121 surrounding the filter chip 11 is formed, and the dam 121 may be formed by, for example, an inkjet printing process. Some process errors are allowed during the process of making the dam 121, for example, the material of the dam 121 may flow to a position under the filter chip 11 on the surface of the circuit board 10, or may contact the solder balls 13 under the filter chip 11, as long as it is ensured that the material of the dam 121 does not contact the first surface S1 of the filter chip 11. Therefore, the process window can be enlarged, and the process difficulty is reduced. In addition, the material of the dam 121 may also flow to the lower side of the adjacent first device, and by filling the gap between the first device and the circuit board 10, the function of underfill (underfill) may be realized, and the reliability of the first device is improved.

As shown in fig. 19, a filling portion 122 that fills a gap between the dam 121 and the filter chip 11 and is in contact with the side wall of the filter chip 11 is formed above the dam 121, and the dam 121 and the corresponding filling portion 122 may constitute the above-described sealing structure. In an actual process, an inkjet printing process may be used to print on the dam 121 at a certain step value toward the filter chip 11, so as to form the filling portion 122 filling the gap between the dam 121 and the corresponding filter chip 11.

As shown in fig. 20, after the filling part 122 is formed, a top cover 123 connected to the filling part 122 may be further formed on the second surface S2 of the filter chip 11. In actual processing, the top cover 123 may be fabricated using an inkjet printing process. Wherein the top cover 123 covers at least the edge of the second surface S2 of the filter chip 11.

Referring to fig. 11, a molding layer 16 is formed to wrap each filter chip 11, each sealing structure 12, and each first device on the circuit board 10. For example, the first device may be an active device 14 or a passive device 15. By encapsulating each filter chip 11 with the molding layer 16, the encapsulation stability of each filter chip 11 can be improved. In the embodiment of the present application, the filter chip 11 and the first device are packaged in the same system-in-package structure, so that the integration level of the system-in-package structure can be effectively improved, the space can be saved, and the manufacturing cost can be reduced. In addition, the filter chip 11 and the first device are conveniently subjected to circuit adaptation, so that the system-in-package structure is simple in structure, the loss of radio-frequency signals is effectively reduced, and the radio-frequency efficiency is improved.

In the actual process, an injection process may be used to form the molding layer 16 on the circuit board 10. During the injection process, the sealing structure 12 may function to prevent the molding compound from contacting the first surface S1 of the filter chip 11. In addition, the sealing structure 12 can also protect the filter chip 11, prevent the filter chip 11 from being damaged by the mold flow pressure generated by the plastic packaging material, and improve the plastic packaging yield. For example, the dam 121 in the sealing structure 12 may prevent the first surface S1 of the filter chip 11 and the solder balls 13 from being damaged, the filling part 122 in the sealing structure 12 may prevent the side wall of the filter chip 11 from being damaged, and the top cover 123 in the sealing structure 12 may prevent the second surface S2 of the filter chip 11 from being damaged.

While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all alterations and modifications as fall within the scope of the application.

It will be apparent to those skilled in the art that various changes and modifications may be made in the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. Thus, if such modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to encompass such modifications and variations.

Claims

1. A board level architecture, comprising: a circuit board, and at least one filter chip and at least one sealing structure located over the circuit board;

the filter chip is provided with an electrode structure on a first surface, and the first surface is the surface of the filter chip facing to one side of the circuit board;

each sealing structure wraps the filter chip;

the sealing structure is in contact with the side wall of the corresponding filter chip, the sealing structure is in contact with the surface of the circuit board, and the sealing structure is not in contact with the first surface of the corresponding filter chip;

the sealing structure, the first surface of the corresponding filter chip and the circuit board form a cavity, and the projection area of the cavity on the circuit board is larger than that of the corresponding filter chip on the circuit board;

the projection area is a projection area in the thickness direction of the circuit board.

2. The board-level architecture of claim 1, wherein a cross-sectional area of the cavity in a direction parallel to the circuit board in a direction of the circuit board toward the filter chip is increased and then decreased or gradually decreased.

3. The board level architecture of claim 2, wherein the sealing structure comprises: a dam located above the circuit board and surrounding the corresponding filter chip, and a filling part located on one side of the dam facing away from the circuit board; the filling part is connected with the box dam, and the filling part fills the gap between the box dam and the corresponding filter chip.

4. The board level architecture of claim 3, wherein the sealing structure further comprises: a top cover connected with the filling part;

the top cover at least covers the edge of the second surface of the corresponding filter chip, and the second surface is the surface of the filter chip on the side departing from the circuit board.

5. The board-level architecture of claim 4, wherein the top cover completely covers the second surface of the filter chip.

6. The board-level architecture of any one of claims 1 to 5, wherein at least two adjacent filter chips are disposed on the circuit board, and each sealing structure corresponding to the at least two adjacent filter chips is an integral structure.

7. A system in a package structure, comprising: the board level architecture of any of claims 1 to 6, and a first device; the first device is located on a circuit board of the board-level architecture.

8. The system-in-package structure of claim 7, further comprising: a plastic encapsulation layer located over the circuit board;

the plastic packaging layer wraps the filter chips, the sealing structures and the first devices on the circuit board.

9. An electronic device, comprising: the system-in-package structure of claim 7 or 8, and a housing encasing the system-in-package structure.

10. A method for manufacturing a board-level architecture is characterized by comprising the following steps:

providing a circuit board and at least one filter chip; the filter chip is provided with an electrode structure on a first surface;

the at least one filter chip is attached to the surface of the circuit board in a direction that the first surface faces the circuit board;

forming a sealing structure which is in contact with the side wall of the filter chip, is in contact with the surface of the circuit board and is not in contact with the first surface of the filter chip at the periphery of at least one filter chip, so that the sealing structure, the first surface of the corresponding filter chip and the circuit board form a cavity; each sealing structure wraps the filter chip, the projection area of the cavity on the circuit board is larger than that of the corresponding filter chip on the circuit board, and the projection area is in the thickness direction of the circuit board.

11. The method of manufacturing of claim 10, wherein the seal structure is manufactured by:

forming a dam around the filter chip; wherein the height of the dam is smaller than the distance between the second surface of the filter chip and the surface of the circuit board, and the second surface is the surface of the filter chip on the side away from the circuit board;

forming a filling part over the dam, filling a gap between the dam and the filter chip, and contacting a sidewall of the filter chip; the box dam and the corresponding filling part form the sealing structure.

12. The manufacturing method according to claim 11, further comprising, after forming the filling portion:

forming a top cover connected with the filling part on the second surface of the filter chip; wherein the top cover covers at least an edge of the second surface of the filter chip.

13. The method of manufacturing according to any one of claims 10 to 12, further comprising, after forming the sealing structure:

and forming a plastic packaging layer wrapping each filter chip and each sealing structure on the circuit board.