CN116156281A

CN116156281A - Micro dead zone intraoral X-ray sensor

Info

Publication number: CN116156281A
Application number: CN202310279712.0A
Authority: CN
Inventors: 陈强江; 韩愚
Original assignee: Shanghai Handy Medical Equipment Co ltd
Current assignee: Shanghai Handy Medical Equipment Co ltd
Priority date: 2023-03-21
Filing date: 2023-03-21
Publication date: 2023-05-23

Abstract

The invention relates to an X-ray sensor in a micro dead zone port, which comprises an image sensor module and a transmission module, wherein the image sensor module comprises a scintillator, an image sensor and a substrate which are sequentially arranged; after the X-rays are emitted, the scintillator converts the X-rays into optical signals, the image sensor converts the optical signals into electric signals, and the substrate receives and outputs the electric signals; the image sensor adopts a stacking technology, a circuit part is placed below an imaging area, and connection is realized by adopting the stacking technology. The problem of effectively improving the imaging area occupation ratio of the intraoral sensor so as to improve the shooting comfort level is solved; the imaging area of the invention can reach more than 90 percent. The CMOS stacking technology is adopted, the pixel array is independent and the processing units are respectively planar, the number of pixel points which can be accommodated under the original area is increased, the quality of an image is correspondingly increased, and the imaging area can reach 100% except the limitation of a panel packaging frame.

Description

Micro dead zone intraoral X-ray sensor

Technical Field

The invention relates to the field of intraoral sensors, in particular to a microcervice intraoral X-ray sensor.

Background

As shown in fig. 1, a schematic structure of a CMOS image sensor is shown, in which:

imaging area ratio = CMOS active pixel area/housing area;

dead area = housing area-CMOS active pixel area;

for the use of the intraoral sensor, the imaging area occupation ratio is improved, and the appearance can be made smaller when teeth with the same area are shot, so that the shooting comfort level is improved.

The CMOS image sensor, the processing unit ADC, the amplifier, the latch and the like are positioned on the same substrate plane, the logic processing unit occupies part of area, a detection dead zone is formed, and the imaging area cannot be distributed on the whole panel. At present, the small volume, low voltage and low power consumption limit the performance of the sensor product even if the small area is occupied. Under the condition of limitation, the traditional imaging area occupies about 50 to 60 percent.

Disclosure of Invention

Aiming at the problem of effectively improving the imaging area occupation ratio of the intraoral sensor so as to improve the photographing comfort, the intraoral X-ray sensor with the micro dead zone is provided.

The technical scheme of the invention is as follows:

the micro dead zone intraoral X-ray sensor comprises an image sensor module and a transmission module, wherein the image sensor module comprises a scintillator, an image sensor and a substrate which are sequentially arranged;

after the X-rays are emitted, the scintillator converts the X-rays into optical signals, the image sensor converts the optical signals into electric signals, and the substrate receives and outputs the electric signals;

the image sensor adopts a stacking technology, a circuit part is placed below an imaging area, and connection is realized by adopting the stacking technology.

Preferably, the image sensor is a CMOS image sensor.

Preferably, the image sensor is a 3-layer stacked CMOS image sensor: the upper layer is a back-illuminated CMOS image sensor, the middle layer is DRAM, and the lower layer is a logic peripheral circuit.

The transmission module comprises a USB connecting wire.

The photosensitive pixel chip in the image sensor is introduced into a column parallel ADC circuit.

The photosensitive pixel chip and the logic circuit chip in the image sensor are connected through Cu-Cu.

The invention has the beneficial effects that:

the imaging area of the invention can reach more than 90 percent. The CMOS stacking technology is adopted, the pixel array is independent and the processing units are respectively planar, the number of pixel points which can be accommodated under the original area is increased, the quality of an image is correspondingly increased, and the imaging area can reach 100% except the limitation of a panel packaging frame. The increased area of the processing unit layer can be used for optimizing, constructing a chip circuit and further improving imaging quality.

Drawings

FIG. 1 is a schematic diagram of a CMOS image sensor in the background art;

FIG. 2 is a schematic diagram of the overall structure of the present invention;

FIG. 3 is a schematic diagram of the structure of an image sensor according to the present invention;

FIG. 4 is a schematic diagram comparing a stacked sensor of the present invention with a conventional backside-illuminated technology;

FIG. 5 is a schematic diagram showing whether a column-parallel ADC is incorporated in the present invention;

FIG. 6 is a comparative schematic diagram of the present invention utilizing Cu-Cu connections instead of TSVs;

fig. 7 is a schematic diagram of a 3-layer stacked CMOS image sensor according to the present invention.

Detailed Description

The invention will now be described in detail with reference to the drawings and specific examples. The present embodiment is implemented on the premise of the technical scheme of the present invention, and a detailed implementation manner and a specific operation process are given, but the protection scope of the present invention is not limited to the following examples.

An X-ray sensor in micro dead zone port is composed of image sensor and USB line, and the image sensor is composed of CMOS sensor, scintillator and substrate.

1. Structural composition

1) The scintillator is used for converting X-rays into visible light, and the existing technology can achieve that almost the whole surface is an effective area and the size can be customized.

2) The substrate is used for realizing signal connection with CMOS and reading circuit, and the size can be customized.

3) CMOS functions to convert optical signals into electrical signals. As shown in fig. 4, the sensors currently used in the mouth all use the back-illuminated technology, and the imaging area occupation ratio is difficult to increase because the circuits are distributed around the imaging area. The invention adopts a stacking technology, the circuit part is placed under the imaging area, and the connection is realized by adopting the stacking technology.

2. Description of stacking techniques

The pixel transistors and photodiodes of the stacked CMOS image sensor are arranged adjacent to each other on the same substrate, and the pixel chip structure used is composed of back-illuminated pixels stacked on top of the logic chip. The pixel chip forms a signal processing circuit on the logic chip. The pixel transistor for controlling a signal and the photodiode for converting light into an electrical signal are arranged adjacent to each other on the same layer substrate.

Wherein the logic circuits are directly integrated on the base wafer. The stacking process allows for a higher integration of highly parallel analog-to-digital converters (ADCs) and signal processing elements in more advanced CMOS processes, independent of the sensor process tailored for the pixel photodiodes. Stacked device architecture continues to change image sensor architecture greatly.

In the dual-layer stacked CMOS image sensor, AMP (amplifier transistor), RST (reset transistor), and SEL (select transistor) are not on the same substrate layer as the photodiodes, and thus noise generated in the image sensor in the dark or at night can be reduced by increasing the size of the amplifier transistor.

The stacked structure of the CMOS image sensor makes it possible to construct chips and perform technical optimization for the pixel unit and the circuit unit, respectively, so that the pixel unit can be optimized for high image quality and the circuit unit can be optimized for high performance.

As shown in fig. 5, the introduction of column parallel ADCs contributes to the improvement of CMOS image sensor performance, especially the frame rate at high resolution. Column parallel ADCs, i.e., ADCs are arranged side-by-side in the vertical column of each photosensitive pixel. Thus, the analog signal read on the vertical signal line can be directly transmitted to the ADC of each column with the shortest length, thereby suppressing the problem of image quality degradation caused by noise mixed in the analog signal transmission, and simultaneously, the signal can be read at high speed. In addition, by means of the double noise reduction technology of high-precision noise reduction by the aid of the analog circuit and the digital circuit, noise is reduced.

As shown in fig. 6, the TSV is replaced with a Cu-Cu connection, which is a manner in which the photosensitive pixel chip and the logic circuit chip are directly connected through Cu pads constructed on the respective stacked surfaces. The connection mode does not need to penetrate through the photosensitive pixel chip or a special connection area, so that further miniaturization and production efficiency improvement of the CMOS image sensor can be realized.

With further development of the stacking technology, a 3-layer stacked CMOS image sensor is presented, as shown in fig. 7, in which the upper layer is a backside illuminated CMOS image sensor, the middle layer is a DRAM, and the lower layer is a logic peripheral circuit. The DRAM serves as a frame memory having a high transmission bandwidth and a temporary buffer of image data. Each layer is connected through TSVs, and pixel output signals are connected to logic circuits through two-level TSVs in the peripheral region of the pixel array. And transmitting the image data after digital conversion from the logic circuit at the lower layer to the DRAM chip at the middle layer of the chip for storage. For video recording in a smart phone, pixel readout scanning can be accelerated, so that distortion in shooting a moving object is reduced, and slow-motion shooting is realized at a high frame rate.

The above examples represent only 1 embodiment of the present invention, which is described in more detail and detail, but are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. The micro dead zone intraoral X-ray sensor is characterized by comprising an image sensor module and a transmission module, wherein the image sensor module comprises a scintillator, an image sensor and a substrate which are sequentially arranged;

2. The micro-dead intraoral X-ray sensor of claim 1, wherein the image sensor is a CMOS image sensor.

3. The micro-dead band intraoral X-ray sensor of claim 1, wherein the image sensor is a 3-layer stacked CMOS image sensor: the upper layer is a back-illuminated CMOS image sensor, the middle layer is DRAM, and the lower layer is a logic peripheral circuit.

4. The micro-dead band intraoral X-ray sensor of claim 1, wherein said transmission module comprises a USB connection wire.

5. The micro-dead intraoral X-ray sensor of claim 1, wherein a photosensitive pixel chip within the image sensor incorporates column parallel ADC circuitry.

6. The micro-dead intraoral X-ray sensor of claim 1, wherein the photosensitive pixel chip and logic circuit chip in the image sensor are connected using Cu-Cu.