CN105897218A - Grooved buried hole type surface acoustic filter chip packaging structure and manufacturing method thereof - Google Patents

Abstract

The invention relates to a surface acoustic filter chip packaging structure with buried holes 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) includes an electrode area (1.1) and a sensing area (1.2), a bonding wafer (4) is arranged above the surface acoustic filter chip wafer (1), and a bonding wafer (4) is formed between the bonding wafer (4) and the sensing area (1.2) a cavity (7), the bonded wafer (4) is provided with an opening (8) at the position of the electrode area (1.1), and the opening (8) is filled with conductive glue or electroplated metal (9), A second metal layer (10) is arranged on the surface of the conductive glue or electroplated metal (9), and metal balls (6) are arranged on the second metal layer (10). The invention discloses a groove-buried hole type surface acoustic filter chip packaging structure and a manufacturing method thereof, which can provide a surface acoustic filter device with a smaller area and volume, and has lower manufacturing cost.

Description

Groove buried hole type surface acoustic filter chip packaging structure and manufacturing method thereof

technical field

The invention relates to a groove buried hole type surface acoustic filter chip packaging structure 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 groove buried hole type surface acoustic filter chip packaging structure and its manufacturing method for the above-mentioned prior art, which can provide a surface acoustic filter device with a smaller area and volume, and has Lower manufacturing costs.

The technical solution adopted by the present invention to solve the above-mentioned problems is: a groove-buried hole type 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 surface of the electrode area is provided with a first metal layer, the area of the surface acoustic filter chip wafer except the electrode area and the sensing area is provided with adhesive glue, and a bonding wafer is arranged above the adhesive glue, so A cavity is formed between the bonded wafer and the sensing area, the bonded wafer is provided with a first opening at the position of the electrode region, the first hole is filled with conductive glue or electroplated metal, and the conductive A second metal layer is provided on the surface of the glue or electroplated metal, an insulating layer is provided on the second metal layer, and a second opening is provided on the insulating layer.

A metal ball is arranged in the second opening;

A groove is opened on the back of the bonded wafer, and the groove is located above the sensing area.

A method for manufacturing a groove buried hole type surface acoustic filter chip packaging structure, said method comprising the following process steps:

Step 1. Take a surface acoustic filter chip wafer;

Step 2, preparing the first metal layer in the electrode region of the surface acoustic filter chip wafer;

Step 3: Etching grooves on the bonded wafer

Take a bonded wafer, and etch a groove at the position required by the bonded wafer. The position of the groove corresponds to the position of the electrode area of the surface acoustic filter chip wafer and the position of the chip sensing area;

Step 4. Wafer Bonding

Bonding the bonded wafer with the groove etched in step 3 to the surface acoustic filter chip wafer through adhesive, thereby forming a cavity above the chip sensing area;

Step 5. Etching and opening

Apply photoresist on the bonded wafer surface, expose, develop, etch, and form the first opening above the electrode area;

Step 6. Buried holes

Embedding in the first opening with conductive glue or electroplated metal;

Step 7, preparing the second metal layer

Prepare a second metal layer on the surface of the conductive glue or electroplated metal embedded in the first opening in step six;

Step 8. Prepare the insulating layer

Apply a layer of insulating glue on the second metal layer, and use photolithography and development to expose the subsequent ball planting position to form the second opening;

Step 9. Planting the ball

Carry out ball planting at the ball planting position exposed in step 8;

Step 10. Cutting

Cut into individual products.

Grinding and thinning the bonded wafer between the steps 4 and 5.

The bonded wafer is made of glass material.

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 groove buried Hole type surface acoustic filter chip packaging structure;

2. The packaging structure of the groove buried hole type 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 package structure of a groove-buried-hole type surface acoustic filter chip according to the present invention.

2 to 12 are process flow charts of a method for manufacturing a groove-buried-hole type 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 metal layer 2

Adhesive 3

Bonded Wafer 4

Groove 5

metal ball 6

Cavity 7

First opening 8

Conductive glue or plated metal9

second metal layer 10

insulating layer 11

The second opening 12.

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 groove-buried type 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 Sensing area 1.2, the surface of the electrode area 1.1 is provided with a first metal layer 2, and 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 adhesive glue 3, the adhesive glue 3 is provided with a bonded wafer 4, a cavity 7 is formed between the bonded wafer 4 and the sensing area 1.2, and the bonded wafer 4 is provided with a first opening 8 at the position of the electrode area 1.1, so The first opening 8 is filled with conductive glue or electroplated metal 9, and the surface of the conductive glue or electroplated metal 9 is provided with a second metal layer 10, and an insulating layer 11 is provided on the second metal layer 10. A second opening 12 is disposed on the insulating layer 11, and a metal ball 6 is disposed in the second opening.

The metal balls 6 are in contact with the second metal layer 10 .

A groove 5 is opened on the back of the bonded wafer 4, and the groove 5 is located above the sensing area 1.2.

Its manufacturing method includes the following process steps:

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

Step 2, referring to Fig. 3, preparing the first metal layer in the electrode region of the surface acoustic filter chip wafer;

The surface acoustic filter chip wafer is cleaned, baked, sputtered, coated with photoresist, photoetched, developed, copper plated, photoresist removed, and etched to prepare the first metal layer in the electrode area;

Step 3: Etching grooves on the bonded wafer

Referring to Figure 4, take a bonded wafer and etch a groove at the position required for the bonded wafer. The position of the groove corresponds to the position of the electrode area of the surface acoustic filter chip wafer and the position of the chip sensing area;

Step 4. Wafer Bonding

Referring to Fig. 5, the bonded wafer with the groove etched in step 3 is bonded to the surface acoustic filter chip wafer through the adhesive, thereby forming a cavity above the chip sensing area;

Step five, thinning

Referring to Figure 6, the bonded wafer is ground and thinned;

Step 6. Etching and opening

Referring to Fig. 7, apply photoresist on the bonded wafer surface, expose, develop, etch, and form a first opening above the electrode area;

Step 7. Buried holes

Referring to Figure 8, use conductive glue or electroplated metal to embed in the first opening;

Step 8, preparing the second metal layer

Referring to Fig. 9, a second metal layer is prepared on the surface of the conductive glue or electroplated metal by cleaning, baking, sputtering, coating photoresist, photolithography, development, electroplating copper layer, removing photoresist, and etching;

Step 9. Prepare the insulating layer

Referring to Figure 10, apply a layer of insulating glue on the second metal layer, and use photolithography and development to expose the subsequent ball planting position to form a second opening;

Step 10. Plant the ball

Referring to Figure 11, perform ball planting at the ball planting position exposed in step 9;

Step 11. Cutting

See Figure 12, cut into individual products.

The bonded wafer is made of glass material or other insulating materials;

In the above steps, the fifth step can also be omitted.

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 surface acoustic filter chip packaging structure with buried holes, characterized in that it includes a surface acoustic filter chip wafer (1), and the surface of the surface acoustic filter chip wafer (1) includes an electrode area (1.1) and the sensing area (1.2), the surface of the electrode area (1.1) is provided with a first metal layer (2), and the surface acoustic filter chip wafer (1) except the electrode area (1.1) and the sensing area (1.2) Adhesive glue (3) is provided in the area, and a bonding wafer (4) is arranged above the bonding glue (3), and a cavity is formed between the bonding wafer (4) and the sensing area (1.2) ( 7), the bonded wafer (4) is provided with a first opening (8) at the position of the electrode area (1.1), and the first opening (8) is filled with conductive glue or electroplated metal (9) , the surface of the conductive glue or electroplated metal (9) is provided with a second metal layer (10), the second metal layer (10) is provided with an insulating layer (11), and the insulating layer (11) is provided with There is a second opening (12), and a metal ball (6) is arranged in the second opening. 2. A groove-buried-hole surface acoustic filter chip packaging structure according to claim 1, characterized in that: a groove (5) is opened on the back of the bonded wafer (4), and the groove ( 5) Located above the sensing area (1.2). 3. A method for manufacturing a groove buried hole type surface acoustic filter chip packaging structure, characterized in that the method comprises the following process steps: Step 1. Take a surface acoustic filter chip wafer; Step 2, preparing the first metal layer in the electrode region of the surface acoustic filter chip wafer; Step 3: Etching grooves on the bonded wafer Take a bonded wafer, and etch a groove at the position required by the bonded wafer. The position of the groove corresponds to the position of the electrode area of the surface acoustic filter chip wafer and the position of the chip sensing area; Step 4. Wafer Bonding Bonding the bonded wafer with the groove etched in step 3 to the surface acoustic filter chip wafer through adhesive, thereby forming a cavity above the chip sensing area; Step 5. Etching and opening Apply photoresist on the bonded wafer surface, expose, develop, etch, and form the first opening above the electrode area; Step 6. Buried holes Embedding in the first opening with conductive glue or electroplated metal; Step 7, preparing the second metal layer Prepare a second metal layer on the surface of the conductive glue or electroplated metal embedded in the first opening in step six; Step 8. Prepare the insulating layer Apply a layer of insulating glue on the second metal layer, and use photolithography and development to expose the subsequent ball planting position to form the second opening; Step 9. Planting the ball Carry out ball planting at the ball planting position exposed in step 8; Step 10. Cutting Cut into individual products. 4 . The method for manufacturing a groove-buried-hole surface acoustic filter chip packaging structure according to claim 2 , wherein the bonded wafer is ground and thinned between steps 4 and 5. 5 . 5 . The method for manufacturing a groove-buried hole type surface acoustic filter chip packaging structure according to claim 2 , wherein the bonded wafer is made of glass material or insulating material. 5 . 6. A method for manufacturing a groove-buried-hole type surface acoustic filter chip packaging structure according to claim 2, characterized in that: in step 3, while etching the bonded wafer out of the groove, the subsequent needs Etch and open holes at the position of the ball planting, and step 5 can be omitted.