CN104681533A - Substrate groove-based chip integrated fingerprint identification sensor and manufacturing method thereof - Google Patents

Abstract

The invention discloses a substrate groove-based chip integrated fingerprint identification sensor and a manufacturing method thereof. The sensor consists of a substrate, a storage chip, bonding wires, a special integrated circuit chip, a sensing chip and a plastic package body, wherein a groove is formed in the substrate; the storage chip and the special integrated circuit chip are arranged in the groove and are respectively connected with the substrate through the corresponding bonding wires; the sensing chip is arranged on the upper surface of the substrate, covers the groove and is connected with the substrate through one bonding wire; the plastic package body wraps the sensing chip and the bonding wires; the upper surface of the sensing chip is naked. According to the scheme, the package size is reduced, and a packaging process is more simple and lower in cost.

Description

Chip-integrated fingerprint recognition sensor based on substrate groove and manufacturing method thereof

technical field

The invention relates to technologies such as microelectronic packaging technology, sensor technology, and chip interconnection, in particular to a chip-integrated fingerprint recognition sensor based on substrate grooves and a manufacturing method thereof.

Background technique

With the continuous improvement of the intelligence of terminal products, various sensor chips emerge in endlessly. Sensor chips have expanded the application fields of smart phones, tablet computers and other products. For example, the emergence of fingerprint recognition chips has greatly improved the security of the above products.

At present, a typical fingerprint identification sensor chip includes a semiconductor chip on which an array of sensor elements for sensing is formed as a sensing area. Its biggest feature is that the sensing area on the chip surface interacts with the user's finger to generate electric signal. In order to ensure the accuracy and sensitivity of sensing, the distance between the sensing area and the user’s finger should be as small as possible. According to the current chip technology, the chip pads are generally located on the same surface. , the height of the bonding wire inevitably increases the distance between the sensing area and the outside of the package.

Domestic Goodix Technology Co., Ltd. proposed a method of making steps on the edge of the sensor chip, leading the pads on the surface of the chip to the steps through the conductive layer, and then performing wire bonding (CN201420009042). This approach avoids the influence of the bonding wires on the distance between the array of sensor elements and the outside of the package, which is hereby incorporated by reference. In addition, Apple Inc. of the United States disclosed a patent (US20140285263A1) on sensor packaging, which uses a deposition technique on a silicon substrate to form a sensing area. There is a slope on the edge of the above-mentioned silicon substrate, so as to lead out the electrical signal generated in the sensing area through the conductive layer. The bonding pad of the sensor chip is located under the slope where the silicon substrate is located, which avoids the influence of the bonding wire on the distance between the sensing area and the outside of the package body. This patent is also incorporated herein by reference.

In order to realize the sensing function of the fingerprint recognition sensor, a memory chip for storing sensing signals, such as a Flash chip, and an application-specific integrated circuit chip for signal processing, namely an ASIC chip, are also required. The current fingerprint recognition sensor device requires many discrete assembly steps, in which the fingerprint recognition sensor chip, memory chip and ASIC chip are each a separate component, put together during the assembly or packaging process of the sensor device, that is, the recognition The sensor chips, memory chips and ASIC chips are not packaged together. As the number of discrete components increases, the process steps become increasingly complex, and the manufacturing cost also increases. At the same time, it has an adverse effect on the yield and reliability of the final product, and the assembly or packaging process of discrete components is time-consuming and inefficient.

Contents of the invention

For the problems existing in the prior art, the present invention provides a chip-integrated fingerprint recognition sensor based on substrate grooves and its manufacturing method. Inside, this solution not only reduces the size of the package, but also makes the packaging process simpler and lower in cost.

A chip-integrated fingerprint recognition sensor based on substrate grooves, the sensor is composed of substrates, memory chips, bonding wires, ASIC chips, sensor chips, and plastic packages; the substrate has grooves, and the memory chips and special integration The circuit chip is in the groove, and the two are respectively connected to the substrate through bonding wires; the sensor chip is on the upper surface of the substrate and covers the groove, and is connected to the substrate through bonding wires; the plastic package wraps the sensor chip and the substrate welding wire.

The upper surface of the sensor chip is exposed, which can improve the sensing effect.

The bare space on the upper part of the sensing chip has a sapphire, glass or ceramic cover sheet.

The plastic package fills the groove of the substrate and wraps the storage chip, the ASIC chip and the bonding wire, so that the position of the chip and the bonding wire can be stabilized without displacement due to external force.

The manufacturing method of the chip-integrated fingerprint recognition sensor based on the groove of the substrate is specifically carried out according to the following steps:

Step 1: making grooves on the substrate;

Step 2: Using a bonding process, the memory chip and the ASIC chip are in the groove, and the two are respectively connected to the substrate through bonding wires;

Step 3: Using a bonding process, the sensor chip is on the upper surface of the substrate and covers the groove, which is connected to the substrate through a wire;

Step 4: The plastic package wraps the sensor chip and the bonding wire, fills the groove of the substrate, and wraps the memory chip, the ASIC chip and the bonding wire.

Wrap the sensor chip with the plastic package as described in step 4, remove the plastic package on the upper part of the sensor chip, and keep the upper surface of the sensor chip exposed.

As in step 4, the partial plastic packaging technology is adopted, and the plastic packaging body wraps the sensor chip to keep the upper surface of the sensor chip exposed.

The connection between the storage chip and the ASIC chip and the substrate may adopt a flip-chip process.

Using this structure, the separate fingerprint identification sensor chip, storage chip and ASIC chip are integrated in the same package, which avoids the cumbersome assembly steps of discrete chip devices, simplifies the process flow, and improves the yield rate of packaged products. At the same time, digging grooves on the substrate avoids making gaskets on the substrate. The stacking method of the structure can make the size of the packaged product smaller and the integration level higher.

Description of drawings

Figure 1 is a substrate diagram with grooves;

Figure 2 is a diagram of bonding the upper core in the groove of the substrate;

Fig. 3 is the bonding diagram of the core on the induction chip;

Figure 4 is the overall plastic package;

Fig. 5 is a diagram of a partially plastic-encapsulated bare sensor chip.

In the figure, 1 is a substrate, 2 is a storage chip, 3 is a bonding wire, 4 is an ASIC chip, 5 is a sensor chip, and 6 is a plastic package.

Detailed ways

The present invention will be further described below according to the accompanying drawings.

As shown in Figure 4, the chip integrated fingerprint recognition sensor based on the substrate groove, the sensor is composed of a substrate 1, a memory chip 2, a bonding wire 3, an ASIC chip 4, a sensor chip 5, and a plastic package 6; The substrate 1 has a groove, and the storage chip 2 and the ASIC chip 4 are in the groove, and both are respectively connected to the substrate 1 through bonding wires 3; the sensor chip 5 is on the upper surface of the substrate 1 and covers the groove. The groove is connected to the substrate 1 through the bonding wire 3 ; the plastic package 6 wraps the sensor chip 5 and the bonding wire 3 .

The upper surface of the sensor chip 5 is exposed, which can improve the sensing effect.

The bare space on the upper part of the sensing chip 5 has a sapphire, glass or ceramic cover.

The plastic package 6 fills the groove of the substrate 1 and wraps the memory chip 2, the ASIC chip 4 and the bonding wire 3, which can stabilize the position of the chip and the bonding wire without displacement due to external force.

The manufacturing method of the chip-integrated fingerprint recognition sensor based on the groove of the substrate is specifically carried out according to the following steps:

Step 1: making grooves on the substrate 1, as shown in Figure 1;

Step 2: Using a bonding process, the memory chip 2 and the ASIC chip 4 are in the groove, and the two are respectively connected to the substrate 1 through the bonding wire 3, as shown in FIG. 1 ;

Step 3: Using a bonding process, the sensor chip 5 is on the upper surface of the substrate 1 and covers the groove, and it is connected to the substrate 1 through the bonding wire 3, as shown in FIG. 3 ;

Step 4: The plastic package 6 wraps the sensor chip 5 and the bonding wire 3 , fills the groove of the substrate 1 , and wraps the memory chip 2 , the ASIC chip 4 and the bonding wire 3 , as shown in FIG. 4 .

As described in step 4, the sensor chip 5 is wrapped with the plastic package 6 , and the plastic package 6 on the upper part of the sensor chip 5 is removed to keep the upper surface of the sensor chip 5 exposed, as shown in FIG. 4 .

As in step 4, the partial plastic encapsulation technique is adopted, and the plastic encapsulation body 6 wraps the sensor chip 5 to keep the upper surface of the sensor chip 5 exposed, as shown in FIG. 4 .

The connection of the storage chip 2 and the ASIC chip 4 to the substrate 1 may adopt a flip-chip process.

Claims (8)

1. The chip-integrated fingerprint recognition sensor based on substrate groove, is characterized in that, described sensor is made of substrate (1), memory chip (2), bonding wire (3), application-specific integrated circuit chip (4), sensing chip ( 5), a plastic package (6); the substrate (1) has a groove, the memory chip (2) and the application specific integrated circuit chip (4) are in the groove, and the two are respectively connected to each other through the bonding wire (3) The substrate (1) is connected; the sensor chip (5) is on the upper surface of the substrate (1), and covers the groove, which is connected to the substrate (1) through the welding wire (3); the plastic package (6) wraps sensor chip (5) and bonding wire (3). 2. The chip-integrated fingerprint recognition sensor based on substrate grooves according to claim 1, characterized in that the upper surface of the sensing chip (5) is exposed. 3. The chip-integrated fingerprint recognition sensor based on substrate grooves according to claim 2, characterized in that, the exposed space on the upper part of the sensing chip (5) has a sapphire, glass or ceramic cover. 4. The chip-integrated fingerprint recognition sensor based on the substrate groove according to claim 1, characterized in that, the plastic package (6) fills the groove of the substrate (1), and wraps the memory chip (2), dedicated integrated Circuit chip (4) and bonding wire (3). 5. The manufacturing method of the chip-integrated fingerprint recognition sensor based on the groove of the substrate, is characterized in that, specifically according to the following steps: Step 1: making grooves on the substrate (1); Step 2: using a bonding process, the memory chip (2) and the ASIC chip (4) are in the groove, and the two are respectively connected to the substrate (1) through the bonding wire (3); Step 3: Using a bonding process, the sensing chip (5) is on the upper surface of the substrate (1) and covers the groove, and is connected to the substrate (1) through a bonding wire (3); Step 4: The plastic package (6) wraps the sensor chip (5) and the bonding wire (3), and fills the groove of the substrate (1), and wraps the memory chip (2), the ASIC chip (4) and the bonding wire (3). 6. The manufacturing method of the chip-integrated fingerprint recognition sensor based on substrate groove according to claim 5, characterized in that, the plastic package (6) as described in step 4 wraps the sensor chip (5), and the sensor chip (5) The upper plastic package (6) is removed to keep the upper surface of the sensor chip (5) exposed. 7. The method for making a chip-integrated fingerprint recognition sensor based on substrate grooves according to claim 5, characterized in that, as in step 4, a partial plastic packaging technique is adopted, and the plastic package (6) wraps the sensing chip (5 ), keeping the upper surface of the sensing chip (5) bare. 8. the manufacture method of the chip-integrated fingerprint recognition sensor based on substrate groove according to claim 5, is characterized in that, the connection of described storage chip (2) and ASIC chip (4) and substrate (1) adopts flip process.