阅读说明：本技术 一种对薄膜体声波滤波器进行封装的方法和封装器件 (Method for packaging film bulk acoustic wave filter and packaging device ) 是由 倪烨 孟腾飞 徐浩 王君 于 2020-12-15 设计创作，主要内容包括：本发明涉及一种对薄膜体声波滤波器进行封装的方法和封装器件,首先,在设有至少一个薄膜体声波滤波器的晶圆上设置多个金球凸点,得到键合晶圆,对所述键合晶圆进行切割,得到至少一个具有薄膜体声波滤波器的切割件,金球凸点的两端分别连接薄膜体声波滤波器的电极以及封装基板上的金属电极,实现薄膜体声波滤波器与封装基板之间的电气互联,然后,采用树脂材料对至少一个切割件进行封装固化,得到固化封装基板,并对所述固化封装基板进行切割,得到至少一个具有薄膜体声波滤波器的封装器件,封装过程简单,不需要采用多次光刻套刻及刻蚀,实现了封装器件的批量生产,效率高,成本低,提升薄膜体声波滤波器在民用领域的市场竞争力。(The invention relates to a method for packaging film bulk acoustic wave filter and a packaging device, firstly, a plurality of gold ball salient points are arranged on a wafer provided with at least one film bulk acoustic wave filter to obtain a bonded wafer, the bonded wafer is cut to obtain at least one cutting piece with the film bulk acoustic wave filter, two ends of the gold ball salient points are respectively connected with an electrode of the film bulk acoustic wave filter and a metal electrode on a packaging substrate to realize the electrical interconnection between the film bulk acoustic wave filter and the packaging substrate, then, at least one cutting piece is packaged and solidified by adopting resin materials to obtain a solidified packaging substrate, the solidified packaging substrate is cut to obtain at least one packaging device with the film bulk acoustic wave filter, the packaging process is simple, multiple photoetching alignment and etching are not needed, and the batch production of the packaging device is realized, the efficiency is high, and is with low costs, promotes the market competitiveness of film bulk acoustic wave filter in civilian field.)

1. A method of packaging a thin film bulk acoustic wave filter, comprising:

respectively arranging gold ball salient points on different electrodes of at least one film bulk acoustic wave filter on a wafer to obtain a bonded wafer, wherein a plurality of gold ball salient points are distributed on the periphery of each film bulk acoustic wave filter;

cutting the bonded wafer to obtain at least one cutting piece with a film bulk acoustic wave filter;

fixing the other end of each gold ball salient point of at least one cutting piece with a corresponding metal electrode respectively so as to enable the film bulk acoustic wave filter of each cutting piece to be located in a corresponding cavity respectively, wherein the metal electrode is arranged on a packaging substrate, and the cavity is formed by the cutting piece and the packaging substrate in a surrounding mode;

and on the packaging substrate, packaging and curing at least one cutting piece by adopting a resin material to obtain a cured packaging substrate, and cutting the cured packaging substrate to obtain at least one packaging device with the film bulk acoustic wave filter.

2. The method as claimed in claim 1, wherein the disposing gold ball bumps on different electrodes of at least one thin film bulk acoustic filter on the wafer respectively comprises:

gold ball bumps are respectively arranged on different electrodes of at least one film bulk acoustic wave filter on the wafer by adopting a gold ball bonding process.

3. A method of packaging a thin film bulk acoustic wave filter according to claim 2, wherein the diameter of the gold wire used in the gold wire ball bonding process is in the range of 15 μm to 38 μm.

4. A method of packaging a thin film bulk acoustic filter according to any of claims 1 to 3, wherein the diameter of the gold ball bump is in the range of 30 μm to 70 μm and the thickness of the gold ball bump is in the range of 15 μm to 25 μm.

5. A method of packaging a thin film bulk acoustic filter according to any of claims 1 to 3, wherein said dicing the bonded wafer comprises:

and cutting the bonded wafer by adopting a laser invisible cutting process.

6. A method for packaging a thin film bulk acoustic filter according to any of claims 1 to 3 wherein the wafer is made of silicon.

7. A method of packaging a thin film bulk acoustic filter according to any of claims 1 to 3, wherein the dicing the cured package substrate comprises:

and cutting the cured packaging substrate by adopting a grinding wheel scribing process.

8. A packaged device manufactured by a method of packaging a thin film bulk acoustic wave filter according to any of claims 1 to 7.

Technical Field

The invention relates to the technical field of film bulk acoustic wave filters, in particular to a method and a packaging device for packaging a film bulk acoustic wave filter.

Background

The Film Bulk Acoustic wave filter (FBAR filter for short) is a device based on Bulk Acoustic wave theory and using Acoustic resonance to realize electrical frequency selection, and the piezoelectric Film between the electrodes of the Film Bulk Acoustic wave filter resonates in the direction perpendicular to the Film Bulk Acoustic wave filter to realize frequency selection, and the basic structure mainly comprises an air gap structure and a reflection array type structure, wherein the piezoelectric Film is made of AlN or ZnO.

The film bulk acoustic wave filter is more and more widely applied to the field of radio frequency communication by using the excellent characteristics of high frequency, high rectangular coefficient, high power resistance, low loss and the like, and as communication systems and terminals are developed towards miniaturization, components in the systems are required to have miniaturization characteristics, most of packaging products of the film bulk acoustic wave filter adopt a Wafer Level Package (WLP) technology at present, and the packaging process mainly comprises the following steps: and manufacturing a cavity structure on the packaging wafer, etching a silicon deep hole, bonding the device wafer and the packaging wafer by manufacturing a metal sealing structure, thinning the packaging wafer, performing silicon deep hole sputtering electroplating and electrode manufacturing, and finally cutting to obtain the independent packaging device with the film bulk acoustic wave filter. According to the above, the wafer level packaging technology needs to perform photolithography, alignment and etching for multiple times to obtain the packaged device with the film bulk acoustic wave filter, and the process is complex, which results in problems of long production period, high production cost, and the like.

Disclosure of Invention

The invention provides a method for packaging a film bulk acoustic wave filter and a packaging device, aiming at the defects of the prior art.

The technical scheme of the method for packaging the film bulk acoustic wave filter is as follows:

respectively arranging gold ball salient points on different electrodes of at least one film bulk acoustic wave filter on a wafer to obtain a bonded wafer, wherein a plurality of gold ball salient points are distributed on the periphery of each film bulk acoustic wave filter;

cutting the bonded wafer to obtain at least one cutting piece with a film bulk acoustic wave filter;

fixing the other end of each gold ball salient point of at least one cutting piece with a corresponding metal electrode respectively so as to enable the film bulk acoustic wave filter of each cutting piece to be located in a corresponding cavity respectively, wherein the metal electrode is arranged on a packaging substrate, and the cavity is formed by the cutting piece and the packaging substrate in a surrounding mode;

and on the packaging substrate, packaging and curing at least one cutting piece by adopting a resin material to obtain a cured packaging substrate, and cutting the cured packaging substrate to obtain at least one packaging device with the film bulk acoustic wave filter.

The method for packaging the film bulk acoustic wave filter and the packaging device have the following beneficial effects:

firstly, a plurality of gold ball salient points are arranged on a wafer provided with at least one film bulk acoustic wave filter to obtain a bonded wafer, cutting the bonded wafer to obtain at least one cutting piece with a film bulk acoustic wave filter, wherein two ends of the gold ball salient points are respectively connected with an electrode of the film bulk acoustic wave filter and a metal electrode on the packaging substrate to realize the electrical interconnection between the film bulk acoustic wave filter and the packaging substrate, then, at least one cutting piece is encapsulated and solidified by adopting resin material to obtain a solidified encapsulation substrate, and cutting the solidified packaging substrate to obtain at least one packaging device with the film bulk acoustic wave filter, wherein the packaging process is simple, multiple photoetching alignment and etching are not needed, the batch production of the packaging device is realized, the efficiency is high, the cost is low, and the market competitiveness of the film bulk acoustic wave filter in the civil field is improved.

On the basis of the above scheme, the method for packaging the thin film bulk acoustic wave filter of the present invention may be further modified as follows.

Further, the method for respectively arranging the gold ball bumps on different electrodes of at least one film bulk acoustic wave filter on the wafer includes:

gold ball bumps are respectively arranged on different electrodes of at least one film bulk acoustic wave filter on the wafer by adopting a gold ball bonding process.

The beneficial effect of adopting the further scheme is that: the stability of the electrical interconnection between the film bulk acoustic wave filter and the packaging substrate can be ensured by adopting a gold wire ball welding process.

Furthermore, the diameter of the gold wire adopted in the gold wire ball welding process is in a range of 15-38 μm.

Furthermore, the diameter range of the gold ball salient point is 30-70 μm, and the thickness range of the gold ball salient point is 15-25 μm.

Further, the dicing the bonded wafer includes: and cutting the bonded wafer by adopting a laser invisible cutting process.

Furthermore, the wafer is made of silicon.

Further, the cutting the cured packaging substrate includes: and cutting the cured packaging substrate by adopting a grinding wheel scribing process.

The technical scheme of the packaging device is as follows:

a packaged device manufactured by the method for packaging a thin film bulk acoustic wave filter according to any one of the above.

Drawings

Fig. 1 is a flowchart illustrating a method for packaging a thin film bulk acoustic filter according to an embodiment of the present invention;

fig. 2 is a second flowchart illustrating a method for packaging a thin film bulk acoustic filter according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of gold ball bumps respectively disposed on different electrodes of at least one FBAR on a wafer;

FIG. 4 is a schematic diagram of a dicing position for dicing a bonded wafer;

FIG. 5 is a schematic view of a structure of a gold ball bump of a cutting member flipped on a metal electrode of a package substrate;

FIG. 6 is a schematic structural diagram of a gold ball bump of a dicing member flip-chip bonded to a metal electrode of a package substrate;

FIG. 7 is a schematic structural diagram after package curing;

fig. 8 is a schematic structural diagram of a packaged device.

In the drawings, the components represented by the respective reference numerals are listed below:

100. a thin film bulk acoustic wave filter; 101. a wafer; 102. gold ball bumps; 103. an electrode; 104. a metal electrode; 105. a cavity; 106. a package substrate; 107. a layer of resin material.

Detailed Description

As shown in fig. 1, a method for packaging a thin film bulk acoustic wave filter according to an embodiment of the present invention includes the following steps:

s1, respectively arranging gold ball bumps 102 on different electrodes 103 of at least one thin film bulk acoustic wave filter 100 on the wafer 101 to obtain a bonded wafer 101, wherein a plurality of gold ball bumps 102 are distributed on the periphery of each thin film bulk acoustic wave filter 100;

s2, cutting the bonded wafer 101 to obtain at least one cutting piece with the film bulk acoustic wave filter 100;

s3, fixing the other end of each gold ball bump 102 of at least one cutting element with a corresponding metal electrode 104, so that the thin film bulk acoustic filter 100 of each cutting element is located in a corresponding cavity 105, wherein the metal electrode 104 is disposed on the package substrate 106, and the cavity 105 is formed by the cutting element and the package substrate 106;

s4, encapsulating and curing the at least one cutting element on the package substrate 106 by using a resin material to obtain a cured package substrate 106, and cutting the cured package substrate 106 to obtain at least one package device with the film bulk acoustic filter 100.

Firstly, a plurality of gold ball salient points 102 are arranged on a wafer 101 provided with at least one film bulk acoustic wave filter 100 to obtain a bonded wafer 101, the bonded wafer 101 is cut to obtain at least one cutting piece with the film bulk acoustic wave filter 100, two ends of each gold ball salient point 102 are respectively connected with an electrode 103 of the film bulk acoustic wave filter 100 and a metal electrode 104 on a packaging substrate 106 to realize the electrical interconnection between the film bulk acoustic wave filter 100 and the packaging substrate 106, then, at least one cutting piece is packaged and cured by adopting a resin material to obtain a cured packaging substrate 106, the cured packaging substrate 106 is cut to obtain at least one packaging device with the film bulk acoustic wave filter 100, the packaging process is simple, multiple photoetching overlay and etching are not needed, the batch production of the packaging device is realized, the efficiency is high, the cost is low, the market competitiveness of the film bulk acoustic wave filter 100 in the civil field is improved.

The fact that the plurality of gold ball bumps 102 are fixed on the wafer 101 through the electrodes 103 of the thin film bulk acoustic filter 100 can be understood as follows: the electrodes 103 of the film bulk acoustic filter 100 are first fixed on the wafer 101, and then the gold ball bumps 102 are respectively and fixedly connected with the corresponding electrodes 103, so that the gold ball bumps 102 are fixed on the wafer 101.

In the following description, three thin film bulk acoustic wave filters 100 are provided on a wafer 101 as an example, each thin film bulk acoustic wave filter 100 is provided with an extracted electrode 103, such as a ground electrode 103 and a signal electrode 103, the signal electrode 103 includes an input signal electrode 103 for inputting a signal and an output electrode 103 for outputting a signal, and the electrode 103 of any thin film bulk acoustic wave filter 100 is distributed around the thin film bulk acoustic wave filter 100, in this case, a gold ball bump 102 is provided on each electrode 103, and a plurality of gold ball bumps 102 are also distributed around each thin film bulk acoustic wave filter 100.

The method for forming the gold ball bumps 102 on the different electrodes 103 of at least one thin film bulk acoustic filter 100 on the wafer 101 includes:

gold ball bumps 102 are respectively arranged on different electrodes 103 of at least one thin film bulk acoustic wave filter 100 on the wafer 101 by adopting a gold ball bonding process. The stability of electrical interconnection between the thin film bulk acoustic wave filter 100 and the package substrate 106 can be ensured by adopting a gold-wire ball bonding process, wherein two ends of each gold-wire ball bump 102 are respectively connected with an electrode 103 of the thin film bulk acoustic wave filter 100 and a metal electrode 104 on the package substrate 106, and the metal electrode 104 specifically comprises an input metal electrode 104 for inputting signals, an input metal electrode 104 for outputting signals and the like; the electrical interconnections are embodied as follows:

when a signal is input to the metal electrode 104, the signal is filtered by sequentially passing through the gold ball bump 102, the input signal electrode 103 of the thin film bulk acoustic filter 100, the output signal electrode 103 of the thin film bulk acoustic filter 100, and the output metal electrode 104.

Wherein, the diameter range of gold wire adopted in the gold wire ball welding process is 15 μm-38 μm, the diameter range of gold ball salient point 102 bonded by the gold wire ball welding process is 30 μm-70 μm, the thickness range of the gold ball salient point 102 is 15 μm-25 μm, and the function is that:

taking the gold ball bumps 102 around any thin film bulk acoustic filter 100 as an example, one end of each gold ball bump 102 around the thin film bulk acoustic filter 100 is connected to a different electrode 103 of the thin film bulk acoustic filter 100, and the other end is connected to a metal electrode 104 arranged on a package substrate 106, because the thickness of the gold ball bump 102 is 15 μm to 25 μm, even after fixed connection, although the thickness after fixed connection is reduced compared with 15 μm to 25 μm, the thickness is still much larger than the thickness of the thin film bulk acoustic filter 100, thereby providing a cavity 105 for the thin film bulk acoustic filter 100; that is to say:

the cutting member and the package substrate 106 surround to form a cavity 105, specifically: a cavity 105 is formed by surrounding each gold ball bump 102, the wafer 101 and the package substrate 106 at the periphery of the thin film bulk acoustic filter 100, that is, the thin film bulk acoustic filter 100 is located in the cavity 105.

Fixing the other end of each gold ball bump 102 of at least one cutting piece with a corresponding metal electrode 104 respectively, so that the thin film bulk acoustic filter 100 of each cutting piece is located in a corresponding cavity 105 respectively, wherein the metal electrode 104 is arranged on a package substrate 106, and the cavity 105 is formed by the cutting piece and the package substrate 106 in a surrounding manner;

preferably, in the above technical solution, the cutting the bonded wafer 101 includes: and cutting the bonded wafer 101 by adopting a laser invisible cutting process.

The laser invisible cutting process is different from the traditional laser surface cutting, laser back cutting and grinding wheel scribing modes, the laser invisible cutting process can effectively avoid pollution caused by redundant materials brought by cutting, meanwhile, the distance between two adjacent cutting pieces can be effectively reduced, the utilization rate of the wafer 101 is further improved, namely, the film bulk acoustic wave filter 100 which is arranged more closely can be arranged on the wafer 101, the generation cost is further reduced, the market competitiveness of the film bulk acoustic wave filter 100 in different fields such as military fields and civil fields is improved, and meanwhile, the laser invisible cutting process has important guiding significance on the packaging products of the film bulk acoustic wave filter 100 of the same type.

Preferably, in the above technical solution, the material of the wafer 101 is silicon.

Preferably, in the above technical solution, the cutting the cured package substrate 106 includes: and cutting the cured packaging substrate 106 by adopting a grinding wheel scribing process.

The electrodes 103 of the film bulk acoustic filter 100 and the metal electrodes 104 of the gold ball bumps 102 are both surface gold-plated structures, and the thickness of the gold layer is greater than 0.5 μm, which can also be adjusted according to actual conditions.

A method for packaging the thin film bulk acoustic filter 100 according to the present application is described in more detail below by another embodiment, as shown in fig. 2, specifically:

s20, setting the gold ball bump 102 to obtain a bonded wafer 101, specifically:

as shown in fig. 3, the electrodes 103 of any one of the thin film bulk acoustic filters 100 are distributed around the thin film bulk acoustic filter 100, and in this case, gold ball bumps 102 are respectively disposed on each electrode 103, so that a plurality of gold ball bumps 102 are also distributed around each thin film bulk acoustic filter 100. Respectively arranging gold ball bumps 102 on different electrodes 103 of at least one film bulk acoustic wave filter 100 on a wafer 101 by adopting a gold ball bonding process to obtain a bonded wafer 101;

wherein, the diameter range of gold wires adopted in the gold wire ball welding process is 15-38 μm, the diameter range of gold ball salient points 102 bonded by the gold wire ball welding process is 30-70 μm, and the thickness range of the gold ball salient points 102 is 15-25 μm;

s21, cutting the bonded wafer 101 to obtain a cut piece, specifically:

the bonded wafer 101 is cut by adopting a laser invisible cutting process to obtain cut pieces, wherein the laser invisible cutting process is different from the traditional laser surface cutting, laser back cutting and grinding wheel scribing modes, the laser invisible cutting process can effectively avoid pollution caused by redundant materials brought by cutting, simultaneously can effectively reduce the distance between two adjacent cut pieces, and further improves the utilization rate of the wafer 101, namely the wafer 101 can be provided with the film bulk acoustic wave filters 100 which are arranged more closely, the generation cost is further reduced, and the market competitiveness of the film bulk acoustic wave filters 100 in different fields such as military fields and civil fields is improved; the specific cutting position is shown by an arrow in fig. 4, and the thin film bulk acoustic filter 100 is not damaged;

s22, flip-chip bonding the gold ball bumps 102 of the cut piece on the metal electrodes 104 of the package substrate 106, specifically:

as shown in fig. 5, the gold ball bumps 102 of the dicing piece are flip-chip mounted on the metal electrodes 104 of the package substrate 106;

as shown in fig. 6, fixing the other end of each gold ball bump 102 of at least one cutting piece with a corresponding metal electrode 104 by using a flip-chip bonding process, so that the thin film bulk acoustic filter 100 of each cutting piece is located in a corresponding cavity 105, respectively, where the metal electrode 104 is disposed on a package substrate 106, and the cavity 105 is formed by the cutting piece and the package substrate 106 surrounding each other;

taking the gold ball bumps 102 around any thin film bulk acoustic filter 100 as an example, one end of each gold ball bump 102 around the thin film bulk acoustic filter 100 is connected to a different electrode 103 of the thin film bulk acoustic filter 100, and the other end is connected to a metal electrode 104 disposed on a package substrate 106, since the thickness of the gold ball bump 102 is 15 μm to 25 μm, even after being fixedly connected, the thickness after being fixedly connected is reduced compared with 15 μm to 25 μm, but still much larger than the thickness of the thin film bulk acoustic filter 100, thereby providing a cavity 105 for the thin film bulk acoustic filter 100; that is to say:

the cutting member and the package substrate 106 surround to form a cavity 105, specifically: a cavity 105 is formed by surrounding each gold ball bump 102, the wafer 101 and the package substrate 106 at the periphery of the thin film bulk acoustic filter 100, that is, the thin film bulk acoustic filter 100 is located in the cavity 105.

S23, performing encapsulation and curing to obtain a cured encapsulation substrate 106, specifically:

as shown in fig. 7, on the package substrate 106, a resin material is used to encapsulate and cure at least one cutting member, so as to obtain a cured package substrate 106, that is, a resin material layer 107 is formed on at least one cutting member, and the resin material layer 107 completely covers the cutting member and is connected to the package substrate 106;

s24, cutting the cured package substrate 106 to obtain a packaged device, specifically:

and cutting the cured package substrate 106 to obtain at least one packaged device with the thin film bulk acoustic filter 100, as shown in fig. 8.

The cured package substrate 106 is cut by a grinding wheel dicing process, so as to obtain at least one package device with the film bulk acoustic wave filter 100.

As shown in fig. 8, a packaged device according to an embodiment of the present invention is a packaged device manufactured by any one of the methods for packaging the thin film bulk acoustic filter 100.

As will be appreciated by one skilled in the art, the present invention may be embodied as a system, method or computer program product.

In the present invention, the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.