CN105897219A - Wafer level surface acoustic filter chip packaging structure and manufacturing method thereof - Google Patents

Abstract

The invention relates to a wafer level surface acoustic filter chip packaging structure and a manufacturing method thereof. The structure comprises a surface acoustic filter chip wafer (1), and the surface of the surface acoustic filter chip wafer (1) includes electrode areas (1.1) and an induction area (1.2). A first metal layer (2) is arranged on the surface of each electrode area (1.1). An insulating layer (3) is arranged on the surface of the surface acoustic filter chip wafer (1). A laminated wafer (4) is arranged above the insulating layer (3). A cavity (7) is formed between the laminated wafer (4) and the induction area (1.2). The laminated wafer (4) is provided with holes (8) at the positions of the electrode areas (1.1), and a metal ball (6) is arranged in each hole (8). According to the wafer level surface acoustic filter chip packaging structure and the manufacturing method thereof of the invention, a surface acoustic filter of smaller area and size and lower manufacturing cost can be provided.

Description

Wafer-level Surface Acoustic Filter Chip Packaging Structure and Manufacturing Method

technical field

The invention relates to a wafer-level 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 wafer-level 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 a lower manufacturing cost.

The technical solution adopted by the present invention to solve the above problems is: a 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 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 an insulating layer, and a bonding wafer is provided above the insulating layer, and the bonding wafer A cavity is formed between the circle and the sensing area, and the bonded wafer is provided with an opening at the position of the electrode area, and a metal ball is provided in the opening, and the metal ball is in contact with the first metal layer.

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

A method for manufacturing a 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, preparing the first metal layer in the electrode region of the surface acoustic filter chip wafer;

Step 3. Prepare the insulating layer

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

Step 4. Wafer Bonding

Take a bonded wafer, apply a layer of adhesive glue on the bonded wafer, and bond it with the surface acoustic filter chip wafer with the insulating layer prepared in step 3, thereby forming a cavity above the sensing area of the chip;

Step 5. Etching

Apply photoresist on the surface of the bonded wafer, and perform exposure, development, and etching to expose the first metal layer of the surface acoustic filter wafer that needs to be ball-planted to form openings;

Step 6. Plant the ball

Carry out ball planting at the position of the exposed first metal layer;

Step 7. Cutting

Cut into individual products.

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

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

The bonded wafer is made of glass material and insulating 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 wafer-level Surface acoustic filter chip packaging structure;

2. The packaging structure of the 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 wafer-level surface acoustic filter chip according to the present invention.

2 to 9 are process flow charts of a manufacturing method of a 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 metal layer 2

Insulation layer 3

Bonded Wafer 4

Adhesive 5

metal ball 6

Cavity 7

Hole 8.

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 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 an electrode area 1.1 and a 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 an insulating layer 3, and the first metal layer 2 and The insulating layer 3 is flush, and a bonding wafer 4 is arranged on the insulating layer 3 through an adhesive 5, and a cavity 7 is formed between the bonding wafer 4 and the sensing area 1.2, and the bonding wafer 4 An opening 8 is provided at the position of the electrode area 1 .

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. Prepare the insulating layer

Referring to Figure 4, 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 4. Wafer Bonding

Referring to Figure 5, take a bonded wafer, apply a layer of adhesive glue on the bonded wafer, and bond it with the surface acoustic filter chip wafer with the insulating layer prepared in step 3, so that the surface acoustic filter chip wafer above the chip sensing area form a cavity;

Step five, thinning

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

Step 6. Etching

Referring to Figure 7, apply photoresist on the surface of the bonded wafer, and perform exposure, development, and etching to expose the first metal layer of the surface acoustic filter wafer that needs to be ball-planted later, and form openings;

Step 7. Plant the ball

Referring to Figure 8, ball planting is performed at the exposed first metal layer position;

Step 8. Cutting

See Figure 9, cut into individual products.

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

The 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 made of glass material or other insulating materials.

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. null1. a wafer level surface sound filtering chip encapsulating structure，It is characterized in that: it includes surface sound filtering chip wafer (1)，Sound filtering chip wafer (1) surface, described surface includes electrode zone (1.1) and induction region (1.2)，Described electrode zone (1.1) surface configuration has the first metal layer (2)，Described surface sound filtering chip wafer (1) region in addition to electrode zone (1.1) and induction region (1.2) is provided with insulating barrier (3)，Described insulating barrier (3) is provided above wafer (4) of fitting，Cavity (7) is formed between described laminating wafer (4) and induction region (1.2)，Described laminating wafer (4) is provided with perforate (8) in electrode zone (1.1) position，Metal ball (6) it is provided with in described perforate (8)，Described metal ball (6) contacts with the first metal layer (2).
2. A kind of wafer level surface the most according to claim 1 sound filtering chip encapsulating structure, it is characterised in that: described laminating wafer (4) is arranged on insulating barrier (3) by adhesive glue (5).
3. 3. the manufacture method of a wafer level surface sound filtering chip encapsulating structure, it is characterised in that described method comprises the following steps that:

   Step one, take a piece of surface sound filtering chip wafer；

   Step 2, prepare the first metal layer at the electrode zone of surface sound filtering chip wafer；

   Step 3, prepare insulating barrier

   Being coated with one layer of insulating cement on the sound filtering chip wafer of surface with coating technique, with photoetching, the insulating cement of electrode zone and chip induction region position is removed by the method for development；

   Step 4, laminating wafer

   Taking a piece of laminating wafer, be coated with last layer adhesive glue on laminating wafer, the surface sound filtering chip wafer preparing insulating barrier with step 3 fits together, thus forms cavity above chip induction region；

   Step 5, etching

   At laminating crystal column surface resist coating, and it is exposed, development, etching, needs the surface sound filtering wafer the first metal layer planting ball to come out follow-up, form perforate；

   Step 6, plant ball

   Carry out planting ball in the first metal layer position come out；

   Step 7, cutting

   Cutting is divided into single product.
4. The manufacture method of a kind of wafer level surface the most according to claim 3 sound filtering chip encapsulating structure, it is characterised in that: between described step 4 and step 5 to laminating wafer be ground, thinning.
5. The manufacture method of a kind of wafer level surface the most according to claim 3 sound filtering chip encapsulating structure, it is characterised in that: described insulating barrier uses B-stage glue, it may be unnecessary to is coated with adhesive glue on laminating wafer, directly fits.
6. The manufacture method of a kind of wafer level surface the most according to claim 3 sound filtering chip encapsulating structure, it is characterised in that: described laminating wafer uses glass material, insulant.