阅读说明：本技术 一种封装结构及其封装方法 (Packaging structure and packaging method thereof ) 是由 郭亚 刘尧清 储莉玲 刘海东 于 2021-08-19 设计创作，主要内容包括：本发明提供一种封装结构及其封装方法,所述封装结构包括：第一半导体圆片,其正面设置有磁传感器、第一金属焊盘和与第一金属焊盘连接的第一再布线层,其背面设置有第一腔体和第二腔体；第二半导体圆片,其正面设置有第二金属焊盘、加速度传感器和陀螺仪,第二半导体圆片与第一半导体圆片的背面相键合,其中,第二半导体圆片位于第一半导体圆片的上方,第二半导体圆片的正面与第一半导体圆片的背面相对,且第二半导体圆片正面的加速度传感器和陀螺仪分别与第一半导体圆片背面的第一腔体和第二腔体相对。与现有技术相比,本发明通过将磁传感器,加速度传感器和陀螺仪集成到一个封装体内部,从而使产品的集成度更高,加工成本更低。(The invention provides a packaging structure and a packaging method thereof, wherein the packaging structure comprises: the front surface of the first semiconductor wafer is provided with a magnetic sensor, a first metal pad and a first rewiring layer connected with the first metal pad, and the back surface of the first semiconductor wafer is provided with a first cavity and a second cavity; and the front surface of the second semiconductor wafer is provided with a second metal bonding pad, an acceleration sensor and a gyroscope, the second semiconductor wafer is bonded with the back surface of the first semiconductor wafer, the second semiconductor wafer is positioned above the first semiconductor wafer, the front surface of the second semiconductor wafer is opposite to the back surface of the first semiconductor wafer, and the acceleration sensor and the gyroscope on the front surface of the second semiconductor wafer are respectively opposite to the first cavity and the second cavity on the back surface of the first semiconductor wafer. Compared with the prior art, the magnetic sensor, the acceleration sensor and the gyroscope are integrated into one packaging body, so that the product integration level is higher, and the processing cost is lower.)

1. A package structure, comprising:

the semiconductor device comprises a first semiconductor wafer (1), wherein a magnetic sensor (101), a first metal pad (102) and a first rewiring layer (103) connected with the first metal pad (102) are arranged on the front surface of the first semiconductor wafer, a first cavity (104) and a second cavity (105) are arranged on the back surface of the first semiconductor wafer, and the first rewiring layer (103) is located below the first metal pad (102);

the front surface of the second semiconductor wafer (2) is provided with a second metal pad (201), an acceleration sensor (202) and a gyroscope (203), the second semiconductor wafer (2) is bonded with the back surface of the first semiconductor wafer (1), the second semiconductor wafer (2) is positioned above the first semiconductor wafer, the front surface of the second semiconductor wafer (2) is opposite to the back surface of the first semiconductor wafer (1), and the acceleration sensor (202) and the gyroscope (203) on the front surface of the second semiconductor wafer (2) are respectively opposite to the first cavity (104) and the second cavity (105) on the back surface of the first semiconductor wafer (1).

2. The package structure of claim 1, further comprising:

and a second rewiring layer (204) which is led out from the second metal pad (201) and redistributed to the back surface of the second semiconductor wafer (2).

3. The package structure of claim 2,

the lead-out mode of the second metal bonding pad (201) is realized in the second semiconductor wafer (2) through a slope metal rewiring process; or

The second metal bonding pad (201) is led out by punching a hole in the second semiconductor wafer (2) and is realized by a through hole process.

4. The package structure of claim 2, further comprising:

solder balls (106) disposed on the first redistribution layer (103) on the front side of the first semiconductor wafer (1).

5. The encapsulation structure according to claim 4, characterized in that it further comprises a substrate (4),

the bonded first semiconductor wafer (1) and the bonded second semiconductor wafer (2) are sequentially stacked from the front side of the substrate (4) to the upper side;

connecting the solder balls (106) on the front surface of the first semiconductor wafer (1) with the substrate (4) through a flip-chip process;

and connecting the second rewiring layer (204) on the back surface of the second semiconductor wafer (2) with the substrate (4) by using a bonding wire (3) through a pressure welding process.

6. The package structure of claim 5, further comprising:

and the plastic packaging material (5) is used for plastically packaging the first semiconductor wafer (1), the second semiconductor wafer (2) and the substrate (4) which are integrated together.

7. A packaging method of a packaging structure is characterized by comprising the following steps:

providing a first semiconductor wafer (1), wherein a magnetic sensor (101), a first metal pad (102) and a first rewiring layer (103) connected with the first metal pad (102) are arranged on the front surface of the first semiconductor wafer (1), a first cavity (104) and a second cavity (105) are arranged on the back surface of the first semiconductor wafer, and the first rewiring layer (103) is positioned below the first metal pad (102);

providing a second semiconductor wafer (2), wherein a front surface of the second semiconductor wafer (2) is provided with a second metal pad (201), an acceleration sensor (202) and a gyroscope (203);

and bonding the second semiconductor wafer (2) with the back surface of the first semiconductor wafer (1), wherein after bonding, the second semiconductor wafer (2) is positioned above the first semiconductor wafer (1), the front surface of the second semiconductor wafer (2) is opposite to the back surface of the first semiconductor wafer (1), and the acceleration sensor (202) and the gyroscope (203) on the front surface of the second semiconductor wafer (2) are respectively opposite to the first cavity (104) and the second cavity (105) on the back surface of the first semiconductor wafer (1).

8. The method of claim 7, comprising:

forming a second rewiring layer (204) on the back of the bonded second semiconductor wafer (2), wherein the second rewiring layer (204) is led out from the second metal pad (201) and is redistributed to the back of the second semiconductor wafer (2);

and arranging solder balls (106) on the first rewiring layer (103) on the front surface of the bonded first semiconductor wafer (1).

9. The method of claim 8,

the lead-out mode of the second metal bonding pad (201) is realized in the second semiconductor wafer (2) through a slope metal rewiring process; or

The second metal bonding pad (201) is led out by punching a hole in the second semiconductor wafer (2) and is realized by a through hole process.

10. The method of claim 8, further comprising:

connecting the solder balls (106) on the back surface of the first semiconductor wafer (1) with the substrate 4 through a flip-chip process;

and connecting the second rewiring layer (204) on the back surface of the second semiconductor wafer (2) with the substrate (4) by using a bonding wire (3) through a pressure welding process.

11. The method of claim 10, further comprising:

and (3) plastically packaging the integrated first semiconductor wafer (1), second semiconductor wafer (2) and substrate (4) by using a plastic packaging material (5) through a plastic packaging process to form a plastic packaging body.

[ technical field ] A method for producing a semiconductor device

The invention relates to the technical field of integrated sensors, in particular to a packaging structure and a packaging method for integrating a magnetic sensor, an acceleration sensor and a gyroscope.

[ background of the invention ]

With the rapid development of the internet of things technology, the application of sensors is gradually popularized, and the application of magnetic sensors, acceleration sensors and gyroscopes in the fields such as consumption, industry and automobile electronics is more and more extensive. However, these sensors with different functions are usually applied as independent products, because the magnetic sensor and other sensors such as accelerometer and gyroscope are manufactured by different processes, and usually require separate flow sheets and then assembled on the same substrate, which takes up more packaging area and cost.

Therefore, it is necessary to provide a technical solution to overcome the above problems.

[ summary of the invention ]

An object of the present invention is to provide a package structure and a packaging method thereof, which integrate a magnetic sensor, an acceleration sensor and a gyroscope into one package, thereby achieving higher integration and lower processing cost of a product.

According to an aspect of the present invention, there is provided a package structure, including: the front surface of the first semiconductor wafer is provided with a magnetic sensor, a first metal pad and a first rewiring layer connected with the first metal pad, and the back surface of the first semiconductor wafer is provided with a first cavity and a second cavity, wherein the first rewiring layer is positioned below the first metal pad; the front surface of the second semiconductor wafer is provided with a second metal bonding pad, an acceleration sensor and a gyroscope, the second semiconductor wafer is bonded with the back surface of the first semiconductor wafer, the second semiconductor wafer is positioned above the first semiconductor wafer, the front surface of the second semiconductor wafer is opposite to the back surface of the first semiconductor wafer, and the acceleration sensor and the gyroscope on the front surface of the second semiconductor wafer are respectively opposite to the first cavity and the second cavity on the surface of the first semiconductor wafer.

According to another aspect of the present invention, there is provided a method of packaging a package structure, including: providing a first semiconductor wafer, wherein the front surface of the first semiconductor wafer is provided with a magnetic sensor, a first metal pad and a first rewiring layer connected with the first metal pad, and the back surface of the first semiconductor wafer is provided with a first cavity and a second cavity, wherein the first rewiring layer is positioned below the first metal pad; providing a second semiconductor wafer, wherein a second metal bonding pad, an acceleration sensor and a gyroscope are arranged on the front surface of the second semiconductor wafer; and bonding the second semiconductor wafer with the back surface of the first semiconductor wafer, wherein the second semiconductor wafer is positioned above the first semiconductor wafer after bonding, the front surface of the second semiconductor wafer is opposite to the back surface of the first semiconductor wafer, and the acceleration sensor and the gyroscope on the front surface of the second semiconductor wafer are respectively opposite to the first cavity and the second cavity on the back surface of the first semiconductor wafer.

Compared with the prior art, the magnetic sensor, the acceleration sensor and the gyroscope are integrated into one packaging body, so that the processing period of a product is shortened, and the processing cost is reduced; on the other hand, the product has higher integration level, reduces the packaging volume and has wider application prospect.

[ description of the drawings ]

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise. Wherein:

FIG. 1 is a schematic longitudinal cross-sectional view of a package structure of an integrated magnetic sensor, an acceleration sensor and a gyroscope according to an embodiment of the present invention;

FIG. 2 is a flow chart illustrating a method for packaging a package structure for integrating a magnetic sensor, an acceleration sensor, and a gyroscope according to an embodiment of the present invention;

fig. 3-10 are longitudinal cross-sectional views corresponding to the steps shown in fig. 2 in one embodiment of the present invention.

[ detailed description ] embodiments

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic may be included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Unless otherwise specified, the terms connected, and connected as used herein mean electrically connected, directly or indirectly.

Fig. 1 is a schematic longitudinal cross-sectional view of a package structure according to an embodiment of the invention, in which a magnetic sensor, an acceleration sensor and a gyroscope are integrated into a package. The package structure shown in fig. 1 includes a first semiconductor wafer 1, a second semiconductor wafer 2, a substrate 4 and a molding compound 5. After the semiconductor wafer level packaging, a semiconductor wafer cutting step is performed to form a plurality of mutually independent packaging structures, i.e. independent chips. The first semiconductor wafer 1 and the second semiconductor wafer 2 are two separate semiconductor wafers in a view before the semiconductor wafers are cut, i.e., in a view at a semiconductor wafer level (i.e., wafer level), and the first semiconductor wafer 1 and the second semiconductor wafer 2 can be understood as wafers of the respective semiconductor wafers in a view after the semiconductor wafers are cut, i.e., in a view at a chip level.

The first semiconductor wafer 1 is a magnetic sensor wafer, the front surface of which is provided with a magnetic sensor (including a structural circuit of the magnetic sensor and a driving circuit thereof) 101, a first metal pad 102, and a first redistribution layer 103 connected to the first metal pad 102, and the back surface of which is provided with a first cavity 104 and a second cavity 105, wherein the first redistribution layer 103 is located below the first metal pad 102; the first rewiring layer 103 is protected by a passivation layer.

The second semiconductor wafer 2 is an acceleration and gyroscope integrated wafer, a second metal pad 201, an acceleration sensor (including a structural circuit of the acceleration sensor and a driving circuit thereof) 202, and a gyroscope (including a structural circuit of the gyroscope and a driving circuit thereof) 203 are arranged on the front surface of the second semiconductor wafer, the second semiconductor wafer 2 is bonded to the back surface of the first semiconductor wafer 1, wherein the second semiconductor wafer 2 is located above the first semiconductor wafer 1, the front surface of the second semiconductor wafer 2 is opposite to the back surface of the first semiconductor wafer 1, and the acceleration sensor 202 and the gyroscope 203 on the front surface of the second semiconductor wafer 2 are respectively opposite to the first cavity 104 and the second cavity 105 on the back surface of the first semiconductor wafer 1.

In one embodiment, the bonding of the first semiconductor wafer 1 and the second semiconductor wafer 2 can be realized by glue bonding, metal bonding or anodic bonding.

In the embodiment shown in fig. 1, a second redistribution layer 204 is disposed on the back surface of the bonded second semiconductor wafer 2 (or the surface of the second semiconductor wafer 2 away from the first semiconductor wafer 1), and is led out from the second metal pad 201 and redistributed to the back surface of the second semiconductor wafer 2, wherein the second metal pad 201 is led out by punching a hole in the second semiconductor wafer 2, and is implemented by a Through Silicon Via (TSV) process, specifically, the second metal pad 201 on the front surface of the second semiconductor wafer 2 is led out to the back surface of the second semiconductor wafer 2 through a metal through line penetrating through the second semiconductor wafer 2 and the second redistribution layer 204, and is protected by a passivation layer. In another embodiment, the second metal pads 201 are led out in the second semiconductor wafer 2 by a ramp metal rewiring process.

Solder balls 106 are provided on the first redistribution layer (103) on the front surface of the first semiconductor wafer (1). Wherein, the metal pads 102, 201 and the solder balls 106 can be used as signal contacts.

The bonded first semiconductor wafer 1 and the bonded second semiconductor wafer 2 are sequentially stacked from the front side of the substrate 4 to the top side, wherein the solder balls 106 on the front side of the first semiconductor wafer 1 are connected with the substrate 4 with the circuit layer inside through a flip chip process; and connecting the second rewiring layer (204) on the back surface of the second semiconductor wafer (2) with the substrate (4) containing a circuit layer by using bonding wires (3) through a pressure welding process, so that the first semiconductor wafer (1), the second semiconductor wafer (2) and the substrate (6) are integrated.

And (3) plastically packaging the integrated first semiconductor wafer 1, second semiconductor wafer 2 and substrate 4 by using a plastic packaging material 5 through a plastic packaging process to form a final packaging body.

Fig. 2 is a schematic flow chart illustrating a packaging method of a package structure according to an embodiment of the invention; referring to fig. 3-10, which are longitudinal sectional views corresponding to the steps shown in fig. 2 according to an embodiment of the present invention. The packaging method of the package structure shown in fig. 2 includes the following steps.

Step 210, as shown in fig. 3, providing a first semiconductor wafer 1, where the first semiconductor wafer 1 is a magnetic sensor wafer, a magnetic sensor (including a structural circuit of the magnetic sensor and a driving circuit thereof) 101, a first metal pad 102, and a first redistribution layer 103 connected to the first metal pad 102 are disposed on a front surface of the first semiconductor wafer, and a first cavity 104 and a second cavity 105 are disposed on a back surface of the first semiconductor wafer, where the first redistribution layer 103 is located below the first metal pad 102; the first rewiring layer 103 is protected by a passivation layer.

Step 220, as shown in fig. 4, providing a second semiconductor wafer 2, where the second semiconductor wafer 2 is an acceleration and gyroscope integrated wafer, and the front surface of the second semiconductor wafer is provided with a second metal pad 201, an acceleration sensor (which includes a structural circuit of the acceleration sensor and a driving circuit thereof) 202, and a gyroscope (which includes a structural circuit of the gyroscope and a driving circuit thereof) 203.

Step 230, as shown in fig. 5, bonding the second semiconductor wafer 2 to the back surface of the first semiconductor wafer 1. After bonding, the second semiconductor wafer 2 is located above the first semiconductor wafer 1, the front surface of the second semiconductor wafer 2 is opposite to the back surface of the first semiconductor wafer 1, and the acceleration sensor 202 and the gyroscope 203 on the front surface of the second semiconductor wafer 2 are respectively opposite to the first cavity 104 and the second cavity 105 on the back surface of the first semiconductor wafer 1.

In one embodiment, the bonding of the first semiconductor wafer 1 and the second semiconductor wafer 2 can be realized by glue bonding, metal bonding or anodic bonding.

Step 240, as shown in fig. 6, a second redistribution layer 204 is formed on the back surface of the bonded second semiconductor wafer 2 (or the surface of the second semiconductor wafer 2 away from the first semiconductor wafer 1), and the second redistribution layer 204 is led out from the second metal pad 201 and redistributed to the back surface of the second semiconductor wafer 2. In the embodiment shown in fig. 6, the second metal pad 201 is extracted by punching a hole in the second semiconductor wafer 2, and is implemented by a Through Silicon Via (TSV) process, specifically, the second metal pad 201 on the front surface of the second semiconductor wafer 2 is extracted to the back surface of the second semiconductor wafer 2 by a metal through line penetrating the second semiconductor wafer 2 and the second redistribution layer 204, and is protected by the passivation layer. In another embodiment, the second metal pads 201 are led out in the second semiconductor wafer 2 by a ramp metal rewiring process.

In step 250, as shown in fig. 7, solder balls 106 are disposed on the first redistribution layer 103 on the front side of the bonded first semiconductor wafer 1. Wherein, the metal pads 102, 201 and the solder balls 106 can be used as signal contacts.

In step 260, as shown in fig. 8, the solder balls 106 on the back surface of the first semiconductor wafer 1 are connected to the substrate 4 by a flip-chip process.

In step 270, as shown in fig. 9, the second redistribution layer 204 on the back surface of the second semiconductor wafer 2 is connected to the substrate 4 by a bonding process using bonding wires 3.

Step 280, as shown in fig. 10, the first semiconductor wafer 1, the second semiconductor wafer 2 and the substrate 4 which are integrated together are subjected to plastic packaging by using a plastic packaging material 5 through a plastic packaging process to form a final package body.

In summary, the magnetic sensor, the acceleration sensor and the gyroscope are integrated into one package, so that on one hand, the product has higher integration level and wider application range; on the other hand, two semiconductor wafers can be simultaneously subjected to wafer level packaging and then scribing after wafer bonding, and then the flip-chip and bonding processes (namely chip routing) are carried out, so that the cost increase and the processing period extension caused by the fact that the wafers respectively flow are avoided.

In the present invention, the terms "connected", "connecting", and the like mean electrical connections, and direct or indirect electrical connections unless otherwise specified.

The above description is only a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above embodiment, but equivalent modifications or changes made by those skilled in the art according to the present disclosure should be included in the scope of the present invention as set forth in the appended claims.