Photodetection assembly and method of manufacture

Abstract

The invention provides a photoelectric detection assembly and a manufacturing method, and is applied to the technical field of laser signal detection. The photoelectric detection assembly comprises a macro photoelectric detector, a macro readout integrated circuit chip, an optical filter, a signal switching substrate and a packaging structure body, the macro photoelectric detectors are connected with the macro readout integrated circuit chip and are respectively arranged at different positions on the signal switching substrate, and the macro photoelectric detectors, the macro readout integrated circuit chip and the signal switching substrate are all arranged in the packaging structure body; the optical filter is located above the macro photoelectric detector, and the optical filter is a part of the packaging structure body; the macro photoelectric detector comprises a plurality of sub-pixels arranged in a two-dimensional array, and the macro readout integrated circuit chip comprises a plurality of trans-impedance amplifiers; and the plurality of sub-pixels are connected with the plurality of trans-impedance amplifiers in a one-to-one correspondence manner.

Description

Technical Field

[0001] The present invention relates to the technical field of laser signal detection, and in particular to a photoelectric detection component and a manufacturing method thereof. Background Art

[0002] Currently, laser detection and ranging sensors based on the laser time of flight (TOF) principle to obtain real-time three-dimensional (3D) images have been widely used. Such sensors can capture 3D images of fast-moving targets, and therefore play an important role in many application fields. To obtain 3D images, such sensors need to process the laser signals reflected from all directions of the region of interest (ROI) in real time.

[0003] In the prior art, the most commonly used laser detection and ranging sensors are usually implemented based on single-pixel detector technology. Its transmitter and receiver generally use two high-speed optical scanners and a large-area photodetector. The transmitter illuminates the focused pulsed laser beam one by one in the specific direction of the ROI through two high-speed optical scanners. The receiver uses a large-area photodetector unit to detect the returned light pulses.

[0004] However, large-area photoelectric detection units not only introduce larger parasitic parameters, but also increase the noise of the receiver, thereby reducing the measurement accuracy of the sensor and the resolution of the 3D image, and having an adverse effect on the detection performance of the system. Summary of the invention

[0005] The present invention provides a photoelectric detection component and a manufacturing method, which are used to solve the problem of reduced measurement accuracy and 3D image resolution of photoelectric detectors in the prior art, and eliminate the adverse effects on system detection performance.

[0006] The present invention provides a photoelectric detection component, comprising: a macro photodetector, a macro readout integrated circuit chip, a filter, a signal switching substrate and a packaging structure body; the macro photodetector is connected to the macro readout integrated circuit chip and is respectively installed at different positions on the signal switching substrate, and the macro photodetector, the macro readout integrated circuit chip and the signal switching substrate are all arranged in the packaging structure body; the filter is located above the macro photodetector, and the filter is a part of the packaging structure body; the macro photodetector includes a plurality of sub-pixels arranged in a two-dimensional array, and the macro readout integrated circuit chip includes a plurality of transimpedance amplifiers; the plurality of sub-pixels are connected to the plurality of transimpedance amplifiers in a one-to-one correspondence.

[0007] According to a photoelectric detection component provided by the present invention, the macro readout integrated circuit chip further includes a comparator, a voltage summing unit and a gating logic circuit.

[0008] According to a photoelectric detection component provided by the present invention, the photoelectric detection component includes a long-distance working mode and a high-resolution working mode.

[0009] According to a photoelectric detection component provided by the present invention, in the long-distance working mode, the photocurrent signals of the sub-pixels of the macro photodetector are amplified by transimpedance amplifiers respectively, summed by the voltage summing unit, and then output to the selection logic circuit.

[0010] According to a photoelectric detection component provided by the present invention, in the high-resolution working mode, the photocurrent signals of the sub-pixels of the macro photodetector are directly output to the selection logic circuit after being amplified by transimpedance amplifiers respectively.

[0011] According to a photoelectric detection component provided by the present invention, the gating logic circuit includes a logic signal output gating logic circuit and an analog signal output gating logic circuit.

[0012] According to a photoelectric detection component provided by the present invention, the analog signal output selection logic circuit takes the signal output of the sub-pixel as input, and the logic signal output selection logic circuit takes the moment identification number as input, and the moment identification number is obtained after the signal of the sub-pixel is input into the comparator.

[0013] According to a photoelectric detection component provided by the present invention, the transimpedance amplifier adopts a single-ended input and single-ended output structure, and its gain is controlled through a control port.

[0014] According to a photoelectric detection component provided by the present invention, the sub-pixel of the macro photodetector is a positive-intrinsic-negative photodiode, an avalanche photodiode or a silicon photomultiplier tube.

[0015] The present invention also provides a method for manufacturing a photoelectric detection component, comprising: making a macro photodetector, the macro photodetector comprising a plurality of sub-pixels, the plurality of sub-pixels being arranged in a two-dimensional array, and the signal of each sub-pixel being able to be individually led out; making a macro readout integrated circuit chip, the number of signal input ports of the macro readout integrated circuit chip being the same as the number of sub-pixels of the macro photodetector; pasting the macro photodetector and the macro readout integrated circuit chip on a signal switching substrate; connecting the signal output end of the macro photodetector with the signal input end of the macro readout integrated circuit chip through a metal wire; connecting the port of the macro photodetector and the port of the macro readout integrated circuit chip to the signal switching substrate by wire bonding respectively; fixing the signal switching substrate carrying the macro photodetector and the macro readout integrated circuit chip in a packaging structure body; connecting the external signal port on the signal switching substrate to a pad inside the packaging structure body through a metal wire; and arranging a filter on a corresponding area of ​​the packaging structure body above the photosensitive area of ​​the macro photodetector.

[0016] The photoelectric detection component and manufacturing method provided by the present invention, the macro photodetector includes a plurality of sub-pixels arranged in a two-dimensional array. Compared with the large-area photoelectric detection unit, the macro photodetector composed of a plurality of sub-pixels can reduce the receiving noise and parasitic parameters while increasing the photosensitive area. In this way, not only the spatial resolution and detection sensitivity can be improved, and the sub-pixel signal link performance can be enhanced; it can also avoid the bandwidth and gain performance of the subsequent signal processing circuit being limited, and avoid the occurrence of problems such as detection failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the structure of a traditional multi-dimensional scanning laser radar system; Figure 2 is a top view of the photoelectric detection assembly provided by the present invention; Figure 3 is a cross-sectional view of the photoelectric detection assembly provided by the present invention; Figure 4 It is a schematic diagram of the structure of the macro readout integrated circuit chip provided by the present invention; Figure 5 is a structural schematic diagram of a voltage summing unit provided by the present invention; Figure 6is a schematic diagram of the structure of a comparator provided by the present invention; Figure 7 It is a structural schematic diagram of the transimpedance amplifier provided by the present invention; Figure 8 It is a schematic flow chart of the method for manufacturing a photoelectric detection component provided by the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0020] It should be noted that, in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0021] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0022] In order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first", "second", etc. are used to distinguish the same items or similar items with basically the same functions and effects. Those skilled in the art can understand that the words "first", "second", etc. are not limiting the quantity and execution order.

[0023] The embodiments of the present application describe some exemplary embodiments for the purpose of explanation. It should be understood that the present application can be implemented in other ways that are not specifically shown in the drawings.

[0024] like Figure 1 The figure shows the structure of a traditional multi-dimensional scanning laser radar system, including a transmitter and a receiver, wherein the transmitter includes two high-speed optical scanners and the receiver includes a large-area photodetector. The transmitter can illuminate the focused pulsed laser beam one by one in a specific direction of the ROI through two two-dimensional scanners. The receiver can use a large-area photodetector to detect the light pulses returned from the target.

[0025] However, traditional multi-dimensional scanning lidar systems have the following problems: (1) The resolution of 3D images is often limited by two 2D scanners. If the spatial resolution is increased, the frame rate will decrease, and if the frame rate is increased, the spatial resolution will decrease. (2) If the photosensitive area of ​​the photodetector is increased, the noise of the receiver will increase. In addition, a large-area single detection unit often brings large parasitic parameters, which limits the bandwidth and gain performance of the subsequent signal processing circuit; (3) Since the dynamic range of the echo signal of the optoelectronic system is extremely large, a single detection unit over a large area is often more easily affected, resulting in problems such as failure to detect or signal saturation, making the detection ineffective.

[0026] In order to solve the above problems, the present application embodiment provides a photoelectric detection component, which is applied to a multi-dimensional scanning laser radar system, such as Figure 2 and Figure 3 As shown, the photoelectric detection component includes: a macro photodetector 10, a macro readout integrated circuit chip 11, a filter 12, a signal transfer substrate 13 and a packaging structure body 14. The macro photodetector 10 can be connected to the macro readout integrated circuit chip 11 through a metal wire, and is respectively installed at different positions on the signal transfer substrate 13. The macro photodetector 10, the macro readout integrated circuit chip 11 and the signal transfer substrate 13 are all arranged in the packaging structure body 14; the filter 12 is located above the macro photodetector 10, and the filter 12 is a part of the packaging structure body 14.

[0027] The macro photodetector 10 is used to realize the photoelectric conversion function, and includes a plurality of sub-pixels arranged in a two-dimensional array. In the design, the filling ratio of the pixel can be increased as much as possible, and a corresponding microlens array can also be added to the pixel.

[0028] The macro readout integrated circuit chip 11 is used to realize the electrical signal processing function, including multiple transimpedance amplifiers, the number of which is consistent with the number of sub-pixels, and the multiple sub-pixels are connected to the multiple transimpedance amplifiers in a one-to-one correspondence. The transimpedance amplifier is used to realize the amplification processing of the photocurrent signal of each sub-pixel, and can process all sub-pixel signals inside the macro photodetector in parallel.

[0029] The signal switching substrate 13 is used to realize the electrical signal connection and switching functions.

[0030] The packaging structure body 14 is used to integrally package the macro photodetector 10 and the macro readout integrated circuit chip 11 for ease of use.

[0031] The filter 12 may use optical filtering of a specific wavelength band, for example, it may be a narrow-band filter of 905 nm or 1550 nm.

[0032] It should be noted that the photoelectric detection component requires the use of peripheral circuits, such as the peripheral circuits providing the required detector high-voltage power supply, signal link power supply, off-chip filtering circuit, temperature sensor, etc.

[0033] In an embodiment of the present application, the macro photodetector includes a plurality of sub-pixels arranged in a two-dimensional array. Compared with a large-area photodetection unit, the macro photodetector composed of a plurality of sub-pixels can reduce receiving noise and parasitic parameters while increasing the photosensitive area. In this way, not only can the spatial resolution and detection sensitivity be improved, and the sub-pixel signal link performance be enhanced; it can also avoid the limitation of the bandwidth and gain performance of the subsequent signal processing circuit, and avoid the occurrence of problems such as detection failure.

[0034] Alternatively, if Figure 4 As shown, the macro readout integrated circuit chip also includes a comparator, a voltage summing unit and a gating logic circuit.

[0035] The voltage summing unit is used to sum all the sub-pixel signals after amplification to obtain a voltage sum signal. Figure 5 As shown, the voltage summing unit includes an operational amplifier and multiple resistors. The operational amplifier is the core component of the voltage summing unit, which is used to amplify and sum the input signal. Multiple resistors play the role of current limiting and voltage division in the circuit. VIN1, VIN2, VIN3 and VIN4 are four input signal sources. The voltage summing unit can first divide the input signal through resistors, and then use the characteristics of the operational amplifier to achieve the summing and amplification function of multiple input signals.

[0036] The comparator is used to identify the sub-pixel signal after amplification. Figure 6As shown, the comparator includes a plurality of MOSFET transistors, and the comparison between the input signal Vin and the reference signal Vref can be realized through the combination of the MOSFET transistors.

[0037] Optionally, the photoelectric detection assembly includes a long-distance working mode and a high-resolution working mode. Figure 4 As shown, in the long-distance working mode, the photocurrent signals of the sub-pixels of the macro photodetector are respectively amplified by the transimpedance amplifier, summed by the voltage summing unit, and then output to the gating logic circuit. In the high-resolution working mode, the photocurrent signals of the sub-pixels of the macro photodetector are respectively amplified by the transimpedance amplifier, and then directly output to the gating logic circuit.

[0038] Taking the array scale of macro photodetectors as M*N as an example, in high-resolution working mode, the measurement point frequency can be directly increased by M*N times. In long-distance working mode, the sub-pixel parasitic parameters can be reduced to 1 / M*N of a single pixel, which can effectively increase the analog bandwidth of the receiving link and increase the detection distance. The above two working modes can be combined according to the preset working sequence and working distance in actual applications.

[0039] Optionally, the gating logic circuit includes a logic signal output gating logic circuit and an analog signal output gating logic circuit. The analog signal output gating logic circuit takes the signal output of the sub-pixel as input, and the logic signal output gating logic circuit takes the moment identification number as input, and the moment identification number is obtained after the signal of the sub-pixel is input into the comparator.

[0040] That is to say, in the long-distance working mode, each sub-pixel is enlarged and then summed, the analog signal output selects the summed signal output, and the digital output signal selects the moment identification digital output of the summed signal. In the high-resolution working mode, each sub-pixel is enlarged and moment identification is performed separately, the analog signal output selects the signal output of each sub-pixel, and the digital output signal selects the moment identification digital output of each sub-pixel.

[0041] In the embodiment of the present application, since multiple sub-pixels are connected one-to-one with multiple transimpedance amplifiers, two working modes can be realized: individual output of each sub-pixel signal and summed output of multiple sub-pixel signals. In this way, the richness of the line configuration can be improved and more application scenarios can be adapted.

[0042] Alternatively, if Figure 7 As shown, the transimpedance amplifier adopts a single-ended input and single-ended output structure, and its gain is controlled through a control port.

[0043] Optionally, the sub-pixel of the macro photodetector is a positive-intrinsic-negative photodiode (PIN), an avalanche photo diode (APD) or a silicon photomultiplier (SIPM).

[0044] like Figure 8 As shown, the embodiment of the present application further provides a method for manufacturing a photoelectric detection component, and the method for manufacturing a photoelectric detection component may include S801-S808: S801. Produce a macro photodetector, wherein the macro photodetector includes a plurality of sub-pixels arranged in a two-dimensional array, and a signal of each sub-pixel can be individually extracted.

[0045] S802, manufacturing a macro readout integrated circuit chip, wherein the number of signal input ports of the macro readout integrated circuit chip is the same as the number of sub-pixels of the macro photodetector.

[0046] S803, pasting the macro photodetector and the macro readout integrated circuit chip onto a signal transfer substrate.

[0047] S804 , connecting the signal output terminal of the macro photodetector and the signal input terminal of the macro readout integrated circuit chip through a metal wire.

[0048] S805 , respectively connecting the port of the macro photodetector and the port of the macro readout integrated circuit chip to the signal transfer substrate by wire bonding.

[0049] S806, fixing the signal transfer substrate carrying the macro photodetector and the macro readout integrated circuit chip in the packaging structure body.

[0050] S807, connecting the external signal port on the signal transfer substrate to the pad inside the packaging structure body through a metal wire.

[0051] S808. Dispose a filter on a corresponding area of ​​the packaging structure body above the photosensitive area of ​​the macro photodetector.

[0052] In an embodiment of the present application, the macro photodetector includes a plurality of sub-pixels arranged in a two-dimensional array. Compared with a large-area photodetection unit, the macro photodetector composed of a plurality of sub-pixels can reduce receiving noise and parasitic parameters while increasing the photosensitive area. In this way, not only can the spatial resolution and detection sensitivity be improved, and the sub-pixel signal link performance be enhanced; it can also avoid the limitation of the bandwidth and gain performance of the subsequent signal processing circuit, and avoid the occurrence of problems such as detection failure.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photoelectric detection component, characterized in that: The multi-dimensional scanning laser radar system includes: macro photodetector, macro readout integrated circuit chip, filter, signal transfer substrate and packaging structure body; The macro photodetector is connected to the macro readout integrated circuit chip and is respectively installed at different positions on the signal transfer substrate. The macro photodetector, the macro readout integrated circuit chip and the signal transfer substrate are all arranged in the package structure body; the filter is located above the macro photodetector, and the filter is a part of the package structure body; The macro photodetector includes a plurality of sub-pixels arranged in a two-dimensional array, and the macro readout integrated circuit chip includes a plurality of transimpedance amplifiers; the plurality of sub-pixels are connected to the plurality of transimpedance amplifiers in a one-to-one correspondence.

2. The photoelectric detection assembly according to claim 1, characterized in that: The macro readout integrated circuit chip also includes a comparator, a voltage summing unit and a gating logic circuit.

3. The photoelectric detection assembly according to claim 2, characterized in that: The photoelectric detection component includes a long-distance working mode and a high-resolution working mode.

4. The photoelectric detection assembly according to claim 3, characterized in that: In the remote working mode, the photocurrent signals of the sub-pixels of the macro photodetector are amplified by the transimpedance amplifiers respectively, summed by the voltage summing unit and then output to the gating logic circuit.

5. The photoelectric detection assembly according to claim 3, characterized in that: In the high-resolution working mode, the photocurrent signals of the sub-pixels of the macro photodetector are directly output to the selection logic circuit after being amplified by the transimpedance amplifiers.

6. The photoelectric detection assembly according to claim 2, characterized in that: The gating logic circuit includes a logic signal output gating logic circuit and an analog signal output gating logic circuit.

7. The photoelectric detection assembly according to claim 6, characterized in that: The analog signal output gating logic circuit takes the signal output of the sub-pixel as input, and the logic signal output gating logic circuit takes the time identification number as input. The time identification number is obtained after the signal of the sub-pixel is input into the comparator.

8. The photoelectric detection assembly according to claim 1, characterized in that: The transimpedance amplifier adopts a single-ended input and single-ended output structure, and its gain is controlled through a control port.

9. The photoelectric detection assembly according to claim 1, characterized in that: The sub-pixel of the macro photodetector is a positive-intrinsic-negative photodiode, an avalanche photodiode or a silicon photomultiplier tube.

10. A method for manufacturing a photoelectric detection component, characterized in that: The following steps are involved: Making a macro photodetector, wherein the macro photodetector comprises a plurality of sub-pixels arranged in a two-dimensional array, and the signal of each sub-pixel can be individually extracted; Making a macro readout integrated circuit chip, wherein the number of signal input ports of the macro readout integrated circuit chip is the same as the number of sub-pixels of the macro photodetector; Pasting the macro photodetector and the macro readout integrated circuit chip on a signal transfer substrate; Connecting the signal output terminal of the macro photodetector to the signal input terminal of the macro readout integrated circuit chip through a metal wire; Connecting the port of the macro photodetector and the port of the macro readout integrated circuit chip to the signal transfer substrate by wire bonding respectively; Fixing the signal transfer substrate carrying the macro photodetector and the macro readout integrated circuit chip in the packaging structure body; Connecting the external signal port on the signal transfer substrate to the pad inside the packaging structure body through a metal wire; A filter is arranged on a corresponding area of ​​the packaging structure body above the photosensitive area of ​​the macro photodetector.

Images