CN105811917A - Metal wafer level surface acoustic filter chip package structure and manufacturing method thereof - Google Patents

Abstract

The invention relates to a packaging structure of a metal wafer-level surface acoustic filter chip and a manufacturing method thereof. The structure includes a surface acoustic filter chip wafer (1), and the surface of the surface acoustic filter chip wafer (1) is provided with a first An insulating layer (2), the first insulating layer (2) is provided with a bonded wafer (4), the surface of the bonded wafer (4) is provided with a second insulating layer (7), and the second The surface of the insulating layer (7) and the surface of the electrode region (1.1) are provided with a first metal layer (8), the surface of the first metal layer (8) is provided with a third insulating layer (9), and the third insulating layer ( 9) A second opening (10) is arranged on the surface, and a metal ball (11) is arranged in the second opening (10), and the metal ball (11) is in contact with the first metal layer (8). The invention discloses a package structure of a metal wafer-level surface acoustic filter chip and a manufacturing method thereof, which can provide a surface acoustic filter device with a smaller area and volume, and has lower manufacturing costs.

Description

Metal wafer-level surface acoustic filter chip packaging structure and manufacturing method thereof

technical field

The invention relates to a packaging structure of a metal wafer-level surface acoustic filter chip and a manufacturing method thereof, belonging to the technical field of semiconductor packaging.

Background technique

Surface acoustic filtering devices are widely used in RF and IF applications, including cellular phones, radiotelephones, and various radios. Through the use of surface acoustic filtering, these electronic devices are processed by filtering and delaying electrical signals. Due to the product performance and design functional requirements of the surface acoustic filter, it is necessary to ensure that the functional area of the filter chip cannot touch any substance, that is, the cavity structure design.

In the existing surface acoustic filter device packaging structure, the filter chip is connected to the ceramic substrate through conductive bump flip-chip welding and completely embedded in the cavity of the substrate, and the surface of the substrate is protected by a metal cover. However, the cost of the metal cover of this structure is relatively high, and the flatness requirements of the ceramic substrate and the metal cover are relatively high, which is prone to poor sealing. In addition, other manufacturing methods of surface acoustic filter devices use top sealing or coating process to seal the module to form a cavity structure.

The existing packaging method of surface acoustic filter devices has a long process, high cost, and relatively large structural size. Under the current trend of electronic equipment becoming smaller and smaller, it is necessary to continuously reduce the size of electronic devices and the components used in them. Weight and dimensions of surface acoustic filter components.

Contents of the invention

The technical problem to be solved by the present invention is to provide a metal wafer-level surface acoustic filter chip packaging structure and its manufacturing method in view of the above-mentioned prior art, which can provide a surface acoustic filter device with a smaller area and volume, and has more Low manufacturing cost.

The technical solution adopted by the present invention to solve the above problems is: a metal wafer-level surface acoustic filter chip packaging structure, which includes a surface acoustic filter chip wafer, and the surface of the surface acoustic filter chip wafer includes an electrode area and a sensing area, The area of the surface acoustic filter chip wafer except the electrode area and the sensing area is provided with a first insulating layer, and a bonded wafer is provided on the first insulating layer, and a bonded wafer is formed between the bonded wafer and the sensing area. A cavity, the bonded wafer is provided with a first opening at the position of the electrode region, the surface of the bonded wafer is provided with a second insulating layer, and the surface of the second insulating layer and the surface of the electrode region are provided with a first A metal layer, the surface of the first metal layer is provided with a third insulating layer, the surface of the third insulating layer is provided with a second opening, and a metal ball is provided in the second opening, and the metal ball and the first The metal layers are in contact.

The bonded wafer is arranged on the first insulating layer through an adhesive.

A method for manufacturing a metal wafer-level surface acoustic filter chip packaging structure, the method comprising the following process steps:

Step 1. Take a surface acoustic filter chip wafer;

Step 2. Prepare the first insulating layer

Apply a layer of insulating glue with a certain thickness on the surface acoustic filter chip wafer by glue coating process, and remove the insulating glue in the electrode area and the sensing area of the chip by photolithography and development;

Step 3: Wafer Bonding

Take a bonded wafer, apply a layer of adhesive on the bonded wafer, and bond it with the surface acoustic filter chip wafer with the first insulating layer prepared in step 2, thereby forming a void above the sensing area of the chip. Cavity;

Step 4. Etching

Apply photoresist on the surface of the bonded wafer, and perform exposure, development, and etching to expose the position of the electrode area of the surface acoustic filter chip wafer to form the first opening;

Step 5. Preparation of the second insulating layer

Apply a layer of insulating glue on the bonded wafer by glue coating process, and remove the insulating glue at the position of the electrode area on the surface acoustic filter chip wafer by photolithography and development;

Step 6. Plating the first metal layer

selectively electroplating the first metal layer on the surface of the electrode area of the surface acoustic filter chip wafer and the surface of the second insulating layer;

Step 7. Prepare the third insulating layer

Apply a layer of insulating glue on the bonded wafer by glue coating process, remove the insulating glue at the subsequent ball planting position by photolithography and developing methods, and form the second opening;

Step 8. Plant the ball

Plant the ball at the planting position;

Step 9. Cutting

Cut into individual products.

Grinding and thinning the bonded wafer between the steps 3 and 4.

The first insulating layer adopts B-stage glue, which can be directly bonded without applying adhesive glue on the bonded wafers.

The bonded wafer is a silicon wafer or a metal material wafer.

Compared with the prior art, the present invention has the advantages of:

1. Compared with the traditional process, the overall production process is at the wafer level, which can form a small-sized packaging structure, and the process is simple, which can ensure the cavity structure of the chip sensing area and form a highly reliable metal wafer Level surface acoustic filter chip packaging structure;

2. The packaging structure of the metal wafer-level surface acoustic filter chip of the present invention can be used directly, or the entire structure and other packaging structures can be packaged on the substrate for secondary packaging to form a system-level package.

Description of drawings

FIG. 1 is a schematic diagram of a packaging structure of a metal wafer-level surface acoustic filter chip according to the present invention.

2 to 11 are process flow charts of Embodiment 1 of a manufacturing method of a metal wafer-level surface acoustic filter chip packaging structure according to the present invention.

in:

Surface Acoustic Filter Chip Wafer 1

Electrode area 1.1

Sensing area 1.2

first insulating layer 2

Adhesive 3

Bonded Wafer 4

Cavity 5

First opening 6

Second insulating layer 7

first metal layer 8

third insulating layer 9

Second opening 10

metal ball11.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, a metal wafer-level surface acoustic filter chip packaging structure in this embodiment includes a surface acoustic filter chip wafer 1, and the surface of the surface acoustic filter chip wafer 1 includes electrode regions 1.1 and induction Area 1.2, the area of the surface acoustic filter chip wafer 1 except the electrode area 1.1 and the sensing area 1.2 is provided with a first insulating layer 2, and a bonded wafer is provided on the first insulating layer 2 through an adhesive 3 4. A cavity 5 is formed between the bonded wafer 4 and the sensing region 1.2, the bonded wafer 4 is provided with a first opening 6 at the position of the electrode region 1.1, and the surface of the bonded wafer 4 is provided with There is a second insulating layer 7, the surface of the second insulating layer 7 and the surface of the electrode region 1.1 are provided with a first metal layer 8, the surface of the first metal layer 8 is provided with a third insulating layer 9, and the third insulating layer The surface of 9 is provided with a second opening 10, and a metal ball 11 is provided in the second opening 10, and the metal ball 11 is in contact with the first metal layer 8.

Its manufacturing method includes the following process steps:

Step 1, see Figure 2, take a surface acoustic filter chip wafer;

Step 2. Prepare the first insulating layer

Referring to Figure 3, apply a layer of insulating glue of a certain thickness on the surface acoustic filter chip wafer with the glue coating process, such as PI (polyimide), PA (nylon, polyamide), and use photolithography and development to paint Removal of the insulating glue in the electrode area and the sensing area of the chip;

Step 3: Wafer Bonding

Referring to Figure 4, take a bonded wafer, apply a layer of adhesive on the bonded wafer, and bond it with the surface acoustic filter chip wafer with the first insulating layer prepared in step 2, so that the sensor on the chip A cavity forms above the area;

Step 4. Thinning

Referring to Figure 5, the bonded wafer is ground and thinned;

Step 5. Etching

Referring to Figure 6, apply photoresist on the surface of the bonded wafer, and perform exposure, development, and etching to expose the position of the electrode area of the surface acoustic filter chip wafer to form the first opening;

Step 6. Prepare the second insulating layer

Referring to Figure 7, apply a layer of insulating glue on the bonded wafer with a glue coating process, such as PI (polyimide), PA (nylon, polyamide), and use photolithography and development to map the position of the electrode area insulation glue removal;

Step 7. Plating the first metal layer

Referring to FIG. 8, the first metal layer is selectively electroplated on the surface of the electrode area of the surface acoustic filter chip wafer and the surface of the second insulating layer;

Step 8. Prepare the third insulating layer

Referring to Figure 9, apply a layer of insulating glue on the bonded wafer with a glue coating process, such as PI (polyimide), PA (nylon, polyamide), and use photolithography and development to place the subsequent ball planting position The insulating glue is removed to form the second opening;

Step 9. Planting the ball

Referring to Figure 10, perform ball planting at the ball planting position;

Step 10. Cutting

See Figure 11, cut into individual products.

In the above steps, the fourth step can be omitted;

The first insulating layer can be B-stage glue, which melts after being heated. At this time, it is not necessary to apply adhesive glue on the bonded wafer, and directly bond it;

The bonded wafer is a silicon wafer or a metal material.

In addition to the above-mentioned embodiments, the present invention also includes other implementations, and any technical solution formed by equivalent transformation or equivalent replacement shall fall within the protection scope of the claims of the present invention.

Claims (6)

1. A metal wafer level surface acoustic filter chip packaging structure, characterized in that it includes a surface acoustic filter chip wafer (1), and the surface of the surface acoustic filter chip wafer (1) includes electrode regions (1.1) and The sensing area (1.2), the area of the surface acoustic filter chip wafer (1) except the electrode area (1.1) and the sensing area (1.2) is provided with a first insulating layer (2), and the first insulating layer (2) ) is provided with a bonded wafer (4), a cavity (5) is formed between the bonded wafer (4) and the sensing area (1.2), and the bonded wafer (4) is in the electrode area (1.1 ) is provided with a first opening (6), the surface of the bonded wafer (4) is provided with a second insulating layer (7), the surface of the second insulating layer (7) and the surface of the electrode region (1.1) A first metal layer (8) is provided, a third insulating layer (9) is provided on the surface of the first metal layer (8), and a second opening (10) is provided on the surface of the third insulating layer (9), A metal ball (11) is arranged in the second opening (10), and the metal ball (11) is in contact with the first metal layer (8). 2. A metal wafer-level surface acoustic filter chip packaging structure according to claim 1, characterized in that: the bonded wafer (4) is arranged on the first insulating layer (2) through adhesive (3) )superior. 3. A method for manufacturing a metal wafer level surface acoustic filter chip packaging structure, characterized in that said method comprises the following process steps: Step 1. Take a surface acoustic filter chip wafer; Step 2. Prepare the first insulating layer Apply a layer of insulating glue with a certain thickness on the surface acoustic filter chip wafer by glue coating process, and remove the insulating glue in the electrode area and the sensing area of the chip by photolithography and development; Step 3: Wafer Bonding Take a bonded wafer, apply a layer of adhesive on the bonded wafer, and bond it with the surface acoustic filter chip wafer with the first insulating layer prepared in step 2, thereby forming a void above the sensing area of the chip. Cavity; Step 4. Etching Apply photoresist on the surface of the bonded wafer, and perform exposure, development, and etching to expose the position of the electrode area of the surface acoustic filter chip wafer to form the first opening; Step 5. Preparation of the second insulating layer Apply a layer of insulating glue on the bonded wafer by glue coating process, and remove the insulating glue at the position of the electrode area by photolithography and development; Step 6. Plating the first metal layer selectively electroplating the first metal layer on the surface of the electrode area of the surface acoustic filter chip wafer and the surface of the second insulating layer; Step 7. Prepare the third insulating layer Apply a layer of insulating glue on the bonded wafer with the glue coating process, and remove the insulating glue at the subsequent ball planting position by photolithography and development to form the second opening; Step 8. Plant the ball Plant the ball at the planting position; Step 9. Cutting Cut into individual products. 4 . The manufacturing method of a metal wafer level surface acoustic filter chip packaging structure according to claim 3 , wherein the bonded wafer is ground and thinned between the step 3 and step 4 . 5. The manufacturing method of a metal wafer-level surface acoustic filter chip packaging structure according to claim 3, characterized in that: the first insulating layer adopts B-stage glue, which does not need to be coated on the bonded wafer. Adhesive glue for direct lamination. 6 . The manufacturing method of a metal wafer level surface acoustic filter chip packaging structure according to claim 3 , wherein the bonded wafer is a silicon wafer or a metal material wafer. 7 .