CN211321304U

CN211321304U - Filter chip packaging structure

Info

Publication number: CN211321304U
Application number: CN201922000079.9U
Authority: CN
Inventors: 王之奇; 胡津津
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-11-18
Filing date: 2019-11-18
Publication date: 2020-08-21
Anticipated expiration: 2029-11-18

Abstract

The utility model provides a wave filter chip packaging structure, wave filter chip packaging structure includes: the front surface of the filter chip is provided with a functional area and a plurality of welding pads arranged around the functional area; a protective film covering the front surface of the filter chip; the supporting enclosing wall is arranged between the protective film and the front surface of the filter chip, a sealing cavity is formed by the supporting enclosing wall, the protective film and the filter chip in an enclosing mode, and the function area is located in the sealing cavity; the support fence covers the welding pads and surrounds the functional area; the position of the protective film corresponding to the welding pad is provided with a through hole, the through hole at least penetrates through the protective film and the supporting enclosing wall, and the through hole exposes the welding pad; and the metal connecting structure is formed in the through hole and is electrically connected with the welding pad.

Description

Filter chip packaging structure

Technical Field

The utility model relates to a semiconductor packaging technology especially relates to the packaging structure of wafer level's wave filter wafer.

Background

The surface acoustic wave filter is an important part of a mobile communication terminal product, and the raw material is made of piezoelectric crystals. The surface acoustic wave filter completes the filtering characteristic by utilizing the excitation, the transmission and the reception of the surface acoustic waves on the piezoelectric material. With the miniaturization and low cost of the mobile terminal, the requirement for packaging the surface acoustic wave filter is also increased correspondingly. Meanwhile, due to the performance and design function requirements of the surface acoustic wave filter product, the functional area of the filter chip is required to be ensured not to contact any substance, namely, the cavity structure design.

Based on the requirements of the surface acoustic wave filter on the cavity structure in the packaging structure and the requirements of the flatness and the cleanliness of the surface of the cavity, the traditional surface acoustic wave filter is mostly packaged by adopting a ceramic substrate, so that the material and the process cost are high, in addition, the thickness and the weight of the ceramic substrate are large, the packaging structure is large in size, the process is complex, meanwhile, the cost performance is low, and the requirements of the packaging structure on thinness, smallness and lightness are satisfied.

SUMMERY OF THE UTILITY MODEL

The utility model provides a need not adopt the filter chip packaging structure of ceramic substrate encapsulation, the technology degree of difficulty and the cost when reducing the encapsulation of filter chip improve the yield of encapsulation, and packaging structure is small.

The utility model provides a wave filter chip packaging structure, include: the front surface of the filter chip is provided with a functional area and a plurality of welding pads arranged around the functional area; a protective film covering the front surface of the filter chip; the supporting enclosing wall is arranged between the protective film and the front surface of the filter chip, a sealing cavity is formed by the supporting enclosing wall, the protective film and the filter chip in an enclosing mode, and the function area is located in the sealing cavity; the support fence covers the welding pads and surrounds the functional area; the position of the protective film corresponding to the welding pad is provided with a through hole, the through hole at least penetrates through the protective film and the supporting enclosing wall, and the through hole exposes the welding pad; and the metal connecting structure is formed in the through hole and is electrically connected with the welding pad.

Preferably, the supporting fence is made of photosensitive glue or curing glue.

Preferably, the protective film is an organic polymer film.

Preferably, the metal connection structure fills the through hole or fills the through hole and protrudes from the front surface of the filter chip.

Preferably, the material of the metal connecting structure comprises one or more of gold, aluminum, copper, silver and tin.

The utility model has the advantages that: the surface of the filter chip is covered by the protective film, the protective film is combined with the supporting enclosing wall to form a cavity, the packaging reliability can be improved, the size of the packaging structure is small, the process flow is greatly simplified, and the cost is reduced. The through hole penetrating through the protective film and supporting the enclosing wall is formed at one time, the welding pad of the filter chip is exposed at the bottom of the through hole, the process is simplified, the metal connecting structure is formed in the through hole, the connecting line length of the welding pad and an external circuit is shortened, and the power consumption of interconnection of devices can be reduced. In addition, the protective film and the supporting enclosing wall are formed on the carrier substrate and then are attached to the filter chip in a transferring mode, so that the process operation on the surface of the filter is reduced, the process flow is simpler and easier to operate, and the damage rate of the filter chip is reduced.

Drawings

Fig. 1 is a schematic structural diagram of a filter chip package structure according to a preferred embodiment of the present invention;

FIG. 2 is a schematic diagram of a wafer-level filter chip wafer and carrier substrate;

FIG. 3 is a schematic structural diagram of a temporary bonding glue layer formed on a carrier substrate;

FIG. 4 is a schematic structural view illustrating a protective film and a carrier substrate aligned and bonded;

FIG. 5 is a schematic diagram of a structure of a patterned support wall formed on a protective film;

FIG. 6 is a schematic diagram illustrating a structure of aligning and pressing a wafer-level filter chip wafer and a protection film;

FIG. 7 is a schematic view of the structure separating the carrier substrate from the protective film;

FIG. 8 is a structural diagram of a via formed in a passivation film at a location corresponding to a pad;

fig. 9 is a schematic structural diagram of forming a metal connection structure in a via.

Detailed Description

The technical solution of the present invention is described in further detail below with reference to the accompanying drawings, but the scope of the present invention is not limited to the following description.

Please refer to fig. 1, which is a schematic structural diagram of a filter chip package structure according to a preferred embodiment of the present invention, the schematic structural diagram is only for clearly showing a positional relationship between components, and the schematic structural diagram does not certainly show a dimensional ratio relationship between the components.

In this embodiment, the filter chip package structure includes: a filter chip 10 having a functional region 11 and a plurality of pads 12 disposed around the functional region on a front surface thereof; the protective film 20 covers the front surface of the filter chip 10; the supporting fence 30 is arranged between the protective film 20 and the front surface of the filter chip 10, a sealed cavity 100 is formed by surrounding among the supporting fence 30, the protective film 20 and the filter chip 10, and the functional region 11 of the filter chip 10 is located in the sealed cavity 100; support fence 30 covers pads 12 and surrounds functional region 11.

The passivation film 20 has through holes corresponding to the pads 12, i.e. each through hole corresponds to one pad 12, the through holes penetrate through the passivation film 20 and the support fence 30, the through holes expose the pads 12, in the embodiment, the bottom of the through holes expose the surface of the pads 12. In other embodiments of the present invention, the through hole can penetrate through the pad 12, so that the pad 12 has a through hole, and the sidewall of the pad 12 corresponding to the through hole is exposed.

The metal connection structures 40 are formed in the through holes, and each metal connection structure 40 is electrically connected to the corresponding pad 12. The metal connection structure 40 electrically connects the pad 12 and an external circuit through the metal connection structure 40.

In the present embodiment, the metal connection structure 40 fills the through hole and protrudes from the front surface of the filter chip 10. In other embodiments of the present invention, the metal connection structure 40 may fill the through hole, i.e., the top surface of the metal connection structure 40 is flush with the front surface of the filter chip 10.

The material of the metal connection structure 40 includes one or more of gold, aluminum, copper, silver, and tin.

In the present embodiment, the material of the supporting walls 30 is an organic polymer-based material, such as a photosensitive glue or a curing glue.

The protective film 20 is an organic polymer film, and a PI film or an acrylic polymer film may be used. The protective film 20 is not easy to deform, an interval is formed between the protective film 20 and the front surface of the filter chip 10 under the support of the support fence 30, and the protective film 20 has good heat resistance and can resist the temperature of the reflow soldering process.

Please refer to fig. 2-9 for a specific wafer level packaging process for forming the filter chip package structure of the present invention. At least comprises the following steps:

referring to fig. 2, a wafer is provided, the wafer is composed of a plurality of filter chips 10 arranged in an array, and a front surface of each filter chip 10 has a functional area 11 and a plurality of bonding pads 12 disposed around the functional area; a carrier substrate 200 is provided, the size of the carrier substrate 200 is not smaller than the size of the wafer, in this embodiment, the carrier substrate 200 is transparent glass.

Referring to fig. 3, a temporary bonding glue layer 300 is formed on the carrier substrate 200. The temporary bonding paste layer 300 may be formed of, for example, a light-heat conversion material, but other types of adhesives may also be used. According to some embodiments of the present invention, the temporary bonding adhesive layer 300 can be decomposed by photo-thermal, and thus the carrier substrate 200 can be separated from the protective film 20.

Referring to fig. 4, a protective film 20 is provided, and the protective film 20 and the carrier substrate 200 are aligned and pressed.

In another embodiment of the present invention, the temporary bonding adhesive layer 300 can be formed on the surface of the protection film 20, and then the protection film and the carrier substrate 200 are aligned and pressed, so that the temporary bonding adhesive layer 300 can be used to bond the protection film 20 and the carrier substrate 200.

In other embodiments of the present invention, the protective film may be liquid, the temporary bonding glue layer 300 may be formed on the carrier substrate 200, and then the protective film is formed on the surface of the temporary bonding glue layer 300 by a coating process, and then a solid protective film is formed by a curing process.

Referring to fig. 5, a patterned supporting fence 30 is formed on the protective film 20. The supporting walls 30 are made of photosensitive resist. The photosensitive glue can be epoxy resin glue, polyimide glue, benzocyclobutene glue, polybenzoxazole glue or the like. The specific process of forming patterned support perimeter walls 30 is: a photosensitive layer covering the surface of the protective film 20 is formed, and the photosensitive layer is subjected to exposure and development processes to form the patterned support fence 30 of the present embodiment. In other embodiments of the present invention, the material of the supporting wall 30 may be a curing glue, and according to the material characteristics of the photosensitive glue or the curing glue, the photosensitive glue or the curing glue may be formed on the protective film 20 by one of the screen printing process, the photolithography process or the glue dispensing process, and then the patterned supporting wall 30 is formed by the photolithography process or the curing process.

Referring to fig. 6, the wafer and the protection film 20 are aligned and pressed, so that a plurality of sealed cavities 100 are formed between the patterned support fence 30, the protection film 20 and the wafer, each sealed cavity 100 corresponds to one filter chip 10, and the functional region 11 of the filter chip 10 is located in the sealed cavity 100.

Referring to fig. 7, the carrier substrate 200 is separated from the protective film 20 by a peeling process, and the temporary bonding adhesive layer 300 loses its adhesiveness by irradiating UV light or laser to the temporary bonding adhesive layer 300 according to the material of the temporary bonding adhesive layer 300, so that the carrier substrate 200 is conveniently separated from the protective film 20.

The utility model discloses a form protection film 20 on carrier substrate 200, then form on protection film 20 and support enclosure 30, then cover the protection film to the wafer of filter chip on, avoid directly forming the support enclosure of patterning on the wafer, so, avoid polluting and damage the wafer, reduced the technology degree of difficulty, simplified process flow.

Referring to fig. 8, a through hole 50 is formed in the passivation film 20 at a position corresponding to the pad 12, the through hole 50 at least penetrates through the passivation film 20 and the support fence 30, and the through hole 50 exposes the pad 12; in the present embodiment, the bottom of the via exposes the surface of the pad 12. In other embodiments of the present invention, the through hole can penetrate through the pad 12, so that the pad 12 has a through hole, and the sidewall of the pad 12 corresponding to the through hole is exposed. In the present embodiment, the via hole 50 is formed by a laser drilling process.

Referring to fig. 9, metal connection structures 40 are formed in the through holes 50, and each metal connection structure 40 is electrically connected to a corresponding pad 12. The metal connection structure 40 electrically connects the pad 12 and an external circuit through the metal connection structure 40.

The process of forming the metal connection structure 40 includes, but is not limited to, a ball-planting process, a gold wire process, an electroplating process, and the like.

Finally, the filter chip package structure shown in fig. 1 is formed through a cutting process.

The present invention has been described above with reference to the accompanying drawings, and it is obvious that the present invention is not limited by the above-mentioned manner, and various insubstantial improvements can be made without the technical solutions of the present invention, or the present invention can be directly applied to other occasions without the improvements, and all are within the scope of the present invention.

Claims

1. A filter chip package structure, comprising:

the front surface of the filter chip is provided with a functional area and a plurality of welding pads arranged around the functional area;

characterized in that, the filter chip packaging structure further comprises:

a protective film covering the front surface of the filter chip;

the supporting enclosing wall is arranged between the protective film and the front surface of the filter chip, a sealing cavity is formed by the supporting enclosing wall, the protective film and the filter chip in an enclosing mode, and the function area is located in the sealing cavity;

the support fence covers the welding pads and surrounds the functional area;

the position of the protective film corresponding to the welding pad is provided with a through hole, the through hole at least penetrates through the protective film and the supporting enclosing wall, and the through hole exposes the welding pad;

and the metal connecting structure is formed in the through hole and is electrically connected with the welding pad.

2. The filter chip package structure of claim 1, wherein the supporting fence is made of a photosensitive adhesive or a curing adhesive.

3. The filter chip packaging structure according to claim 1, wherein the protective film is an organic polymer film.

4. The filter chip packaging structure of claim 1, wherein the metal connection structure fills the through hole or fills the through hole and protrudes from the front surface of the filter chip.

5. The filter chip package structure of claim 1, wherein the metal connection structure comprises one or more of gold, aluminum, copper, silver, and tin.