Photoelectric integrated microsystem 3D packaging structure and manufacturing method thereof

Abstract

The invention belongs to the technical field of microsystems, and particularly relates to a photoelectric integrated microsystem 3D packaging structure and a manufacturing method thereof. Comprising a photoelectric detection module, a signal conditioning module and an operation processing module which are stacked from top to bottom, the photoelectric detection module, the signal conditioning module and the operation processing module are independently packaged, every two adjacent modules are electrically connected, and the photoelectric detection module is provided with a visible light window. Different modules are relatively independent and matched in shape and size, then the multiple functional modules are stacked in a three-dimensional mode in a vertical interconnection mode, the packaging density is high, the packaging projection area is small, the packaging projection shape is a circle or a regular polygon, and the module is suitable for optical detection and signal processing of small-diameter space equipment; each module is independently packaged, the packaging size is small, the modules can be independently manufactured and tested, and the maintainability is good.

Description

Technical Field

[0001] The present invention belongs to the technical field of microsystems, and in particular relates to a 3D packaging structure of an optoelectronic integrated microsystem and a manufacturing method thereof. Background Art

[0002] The optoelectronic integrated microsystem consists of three main functional parts: optical detection, signal conditioning, and operation processing, which can realize functions such as optical signal acquisition, processing, and calculation. The optical detection part can detect and collect optical signals such as visible light, infrared, ultraviolet, and laser, and convert the detected optical signals into weak electrical signals, which are easy to display and identify. The signal conditioning part amplifies and outputs the weak narrow pulse signal, and converts the output signal through the ADC module. The operation processing part analyzes and processes the collected and conditioned signals, and outputs control signals to the actuator.

[0003] The system-level packaging structure is a module that integrates multiple electronic components with different functions into one package to realize a basic complete function. With the widespread application of optoelectronic microsystems in big data, cloud computing, artificial intelligence and other fields, higher requirements are placed on the integration, miniaturization and reliability of the packaging structure.

[0004] The patent with publication number CN112684550A discloses a microsystem packaging structure for optoelectronic transceiver processing, which includes: an integrated tube shell and a microsystem; the microsystem includes an ADC chip, a direct digital frequency synthesizer DDS, a Flash chip, a static random access memory SRAM, a microcontroller unit MCU, a TIA amplifier, a VCSEL laser driver, a VCSEL array laser, a PD array photodetector, a V-groove, a 12-core optical fiber and an FPGA chip; the invention integrates analog-to-digital conversion, digital-to-analog conversion, a programmable digital processor, a memory, photoelectric conversion and electro-optical conversion of radio frequency signals, but still has a large projection area and cannot be used in applications with small diameter spaces; and each part is integrated in the integrated tube shell, which makes maintenance cumbersome and costly. Summary of the invention

[0005] In view of the above problems existing in the prior art, the present invention provides a 3D packaging structure of an optoelectronic integrated microsystem and a manufacturing method thereof, which can solve the problems of large packaging size and high maintenance cost.

[0006] To achieve the above object, the technical solution provided by the present invention is as follows:

[0007] In the first aspect, the present application provides a 3D packaging structure of an optoelectronic integrated microsystem, comprising a photoelectric detection module, a signal conditioning module and an operation processing module stacked from top to bottom, wherein the photoelectric detection module, the signal conditioning module and the operation processing module are all independently packaged, and adjacent modules are electrically interconnected, and the photoelectric detection module has a visible light window.

[0008] Optionally, the photoelectric detection module includes a first substrate, an outer frame and a first cover plate having the visible light window, the outer frame connects the first substrate and the first cover plate to form a photoelectric detection module element installation cavity, the first cover plate is connected to the first substrate through a metal dam, the metal dam is arranged on the inner side of the outer frame, and an independent optical sensor chamber is formed between the first substrate, the metal dam and the first cover plate, and the photoelectric detection module element is electrically connected to the signal conditioning module through the first substrate.

[0009] Optionally, the signal conditioning module includes a second substrate and a second cover plate, the second substrate is provided with a signal conditioning module component installation cavity, the second cover plate closes the signal conditioning module component installation cavity, and the signal conditioning module component is electrically connected to the photoelectric detection module and the operation processing module through the second substrate.

[0010] Optionally, the operation and processing module includes a third substrate and a third cover plate, the third substrate is provided with an operation and processing module component installation cavity, the third cover plate closes the operation and processing module component installation cavity, the operation and processing module component is electrically connected to the signal conditioning module through the third substrate, and the bottom of the third substrate leads out the signal through BGA, LGA or CCGA.

[0011] Optionally, two adjacent modules are electrically interconnected via BGA solder balls.

[0012] Optionally, the projection of the packaging structure parallel to the module arrangement direction is a circle or a regular polygon, and the number of sides of the regular polygon is ≥6.

[0013] Optionally, the first substrate, the second substrate and the third substrate are multi-layer ceramic substrates.

[0014] Optionally, the multilayer ceramic substrate is a LTCC substrate or a HTCC substrate.

[0015] Optionally, a filling glue is filled between two adjacent modules.

[0016] In a second aspect, the present application also provides a method for manufacturing the above-mentioned optoelectronic integrated microsystem 3D packaging structure, comprising the following steps:

[0017] Step 1: Cut and prepare the first substrate, the second substrate and the third substrate according to the required shapes;

[0018] Step 2: Weld the metal dam and the outer frame onto the first substrate, mount the photoelectric sensor in the photoelectric detection module components onto the first substrate in the center of the metal dam, install other photoelectric detection module components onto the first substrate between the outer frame and the metal dam, and then weld the first cover plate without the visible light window to the metal dam and the outer frame; metallize the edge of the visible light window and connect the visible light window to the first cover plate through a solder melting process to obtain a photoelectric detection module;

[0019] Step 3: Assemble the second substrate, the signal conditioning module components and the second cover plate to obtain the signal conditioning module; assemble the third substrate, the operation processing module components and the third cover plate to obtain the operation processing module;

[0020] Step 4: The photoelectric detection module, signal conditioning module and operation processing module are stacked and packaged from top to bottom, and the layers are interconnected by BGA solder balls. During the welding process, the modules between layers are accurately aligned with the help of an automatic alignment system. After the welding is completed, the stacked layers are fixed with filling glue to obtain the 3D packaging structure of the optoelectronic integrated microsystem.

[0021] Compared with the prior art, this application has at least the following beneficial effects:

[0022] 1. Different modules of the present invention are relatively independent, and their shapes and sizes match each other. Then, multiple functional modules are three-dimensionally stacked in a vertically interconnected manner, with high packaging density and small packaging projection area. The packaging projection shape is a circle or a regular polygon (with the number of sides ≥ 6), which is suitable for optical detection and signal processing of small-diameter space equipment;

[0023] Second, each module in the present invention is independently packaged, has a small package size, can be independently manufactured and tested, and has good maintainability;

[0024] 3. Each module adopts airtight packaging, which has high reliability, and the optical sensor has an independent packaging chamber, which can ensure that the optical sensor has better surface cleanliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A schematic diagram of a 3D packaging structure of an optoelectronic integrated microsystem according to Example 2 of the present application;

[0027] Figure 2A schematic diagram of a 3D packaging stereoscopic structure of an optoelectronic integrated microsystem according to Example 2 of the present application;

[0028] Figure 3 This is a schematic diagram of the connection relationship between the visible light window and the first cover plate in Example 2 of the present application;

[0029] Figure 4 This is a schematic diagram of the structure of the photoelectric detection module in Example 2 of the present application;

[0030] Figure 5 This is a schematic diagram of the structure of the second substrate in Example 2 of the present application;

[0031] Description of reference numerals:

[0032] 1. Photoelectric detection module; 11. First substrate; 12. Outer frame; 13. First cover plate; 131. Visible light window; 1311. Solder ring; 14. Photoelectric sensor; 15. Metal dam; 2. Signal conditioning module; 21. Second substrate; 22. Second cover plate; 3. Operation processing module; 31. Third substrate; 32. Third cover plate; 4. BGA solder ball. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application or use.

[0034] Example 1

[0035] A 3D packaging structure of an optoelectronic integrated microsystem includes a photoelectric detection module 1, a signal conditioning module 2 and an operation processing module 3 which are stacked from top to bottom. The photoelectric detection module 1 detects and collects optical signals and converts the detected optical signals into weak electrical signals. The signal conditioning module 2 has functions such as weak signal amplification, peak hold, and digital-to-analog / analog-to-digital conversion. The operation processing module 3 can perform data analysis and generate control signals. The photoelectric detection module 1, the signal conditioning module 2 and the operation processing module 3 are all independently packaged, and adjacent modules are electrically interconnected. The photoelectric detection module 1 has a visible light window 131.

[0036] Different modules are integrated and assembled in a three-dimensional stacking form, which is suitable for optical detection and signal processing of small-diameter space equipment, and can be used in application fields such as target recognition and precise guidance. Each module is independently packaged with a small package size, and can be independently manufactured and tested, with good maintainability.

[0037] Example 2

[0038] like Figure 1-Figure 4 As shown, the difference between this embodiment and embodiment 1 is that: the photoelectric detection module 1 includes a first substrate 11, an outer frame 12 and a first cover plate 13 with a visible light window 131, the first substrate 11 is a planar substrate, the outer frame 12 connects the first substrate 11 and the first cover plate 13 to form a cylindrical photoelectric detection module component installation cavity, the first cover plate 13 is connected to the first substrate 11 through a metal dam 15, the metal dam 15 is arranged on the inner side of the outer frame 12, and an independent photoelectric sensor chamber is formed between the first substrate 11, the metal dam 15 and the first cover plate 13, which isolates the photoelectric sensor 14 from other components to reduce the falling of foreign movable particles on the surface of the photoelectric sensor 14, and the visible light window 131 is connected to the first cover plate 13 through a solder ring 1311, and the optical signal can enter the photoelectric sensor chamber through the visible light window 131. The optical sensor chamber is also cylindrical, and the photoelectric detection module element is electrically connected to the signal conditioning module 2 through the first substrate 11. The photoelectric detection module components generally include a photoelectric sensor 14, an amplifier, a power supply, etc. The photoelectric detection module components are existing technologies and will not be described in detail here.

[0039] The signal conditioning module 2 comprises a second substrate 21 and a second cover plate 22 . The second substrate 21 is provided with a signal conditioning module component installation cavity, and the second cover plate 22 seals the signal conditioning module component installation cavity.

[0040] The operation processing module 3 includes a third substrate 31 and a third cover plate 32. The third substrate 31 is provided with an operation processing module component installation cavity, and the third cover plate 32 closes the operation processing module component installation cavity. The first substrate 11, the second substrate 21 and the third substrate 31 are multilayer ceramic substrates, and the internal wiring of the multilayer ceramic substrates realizes electrical interconnection; the mechanical connection and electrical interconnection between the two adjacent substrates are realized through the BGA solder balls 4, so as to realize electrical connection between different modules. The bottom of the third substrate 31 leads out the signal through the BGA, LGA or CCGA method, which can be selected according to the needs. The signal conditioning module components and the operation processing module components are also existing technologies, which will not be repeated here. Each module adopts airtight packaging with high reliability.

[0041] The multilayer ceramic substrate is an LTCC substrate or an HTCC substrate. The LTCC substrate has smaller transmission delay and high-speed performance, while the HTCC substrate has better structural strength and heat dissipation performance.

[0042] like Figure 5As shown, the projection of the packaging structure along the direction parallel to the module arrangement direction is a circle or a regular polygon, and the number of sides of the regular polygon is ≥6. In this embodiment, the cross-sections of the first substrate 11, the second substrate 21 and the third substrate 31 are all regular octagons, wherein the mounting cavities on the second substrate 21 and the third substrate 31 are octagonal, and the second substrate 21 and the third substrate 31 have the same structure, and the edges of the mounting cavity are parallel to the edges of the substrates to obtain a mounting cavity with a larger accommodating space.

[0043] Filling glue is filled between two adjacent modules to ensure the firmness of the mechanical connection between the layers and the matching of stress.

[0044] Example 3

[0045] The optoelectronic integrated microsystem 3D packaging structure in Example 2 is manufactured by the following method:

[0046] Step 1: The multilayer ceramic substrate used in the present invention is made by a standard multilayer co-fired ceramic substrate process, and the first substrate 11, the second substrate 21 and the third substrate 31 are cut and prepared according to the required shapes using double-sided picosecond laser technology.

[0047] Step 2: Weld the metal dam 15 and the outer frame 12 on the first substrate 11. The outer frame 12 is made of metal made of Kovar material. The photoelectric sensor 14 in the photoelectric detection module is mounted on the first substrate 11 in the center of the metal dam 15. Other photoelectric detection module components are installed on the first substrate 11 between the outer frame 12 and the metal dam 15. Then, the first cover plate 13 without the visible light window 131 is welded to the metal dam 15 and the outer frame 12. The visible light window 131 uses sapphire glass coated with AR anti-reflection film as the glass material of the light window, and then the edge of the visible light window 131 is metallized (nickel-plated gold), and the glass is connected to the first cover plate 13 through a solder ring by a solder sealing process to obtain a photoelectric detection module 1. The welding can be selected as parallel seam welding or laser seam welding as needed. The shell structure of different welding methods is somewhat different. The shell structure of parallel seam welding is generally a step cover plate + a plane frame port, and the laser seam welding is generally a gap welding of a thick plate cover plate + a step frame port.

[0048] Step 3: Assemble the second substrate 21 , the signal conditioning module components and the second cover 22 to obtain the signal conditioning module 2 ; assemble the third substrate 31 , the operation processing module 3 components and the third cover 32 to obtain the operation processing module 3 .

[0049] Step 4: The photoelectric detection module 1, signal conditioning module 2 and operation processing module 3 are stacked and packaged from top to bottom. The layers are interconnected by BGA solder balls 4. The solder balls are high-lead solder balls, which can maintain the initial shape without collapse during the welding process. Due to the large number of BGAs, high-precision BGA mounting is required, such as using an assembly workstation with a spectroscopic alignment system or a placement machine with an automatic alignment system to accurately align the modules between layers. During the overall reflow, the stacked package can be placed in a positioning fixture for welding to reduce the voids at the welding interface and the thickness of the IMC. After welding is completed, the stacked layers are fixed with filling glue to obtain the 3D packaging structure of the optoelectronic integrated microsystem.

[0050] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0051] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A 3D packaging structure of an optoelectronic integrated microsystem, characterized in that: It includes a photoelectric detection module, a signal conditioning module and an operation processing module stacked from top to bottom. The photoelectric detection module, the signal conditioning module and the operation processing module are all independently packaged, and two adjacent modules are electrically interconnected. The photoelectric detection module is provided with a visible light window.

2. The optoelectronic integrated microsystem 3D packaging structure according to claim 1, characterized in that: The photoelectric detection module includes a first substrate, an outer frame and a first cover plate having the visible light window. The outer frame connects the first substrate and the first cover plate to form a photoelectric detection module element installation cavity. The first cover plate is connected to the first substrate through a metal dam. The metal dam is arranged on the inner side of the outer frame. A built-in independent optical sensor chamber is formed between the first substrate, the metal dam and the first cover plate. The photoelectric detection module element is electrically connected to the signal conditioning module through the first substrate.

3. The optoelectronic integrated microsystem 3D packaging structure according to claim 2, characterized in that: The signal conditioning module includes a second substrate and a second cover plate. The second substrate is provided with a signal conditioning module component installation cavity. The second cover plate closes the signal conditioning module component installation cavity. The signal conditioning module components are electrically connected to the photoelectric detection module and the operation processing module through the second substrate.

4. The optoelectronic integrated microsystem 3D packaging structure according to claim 3, characterized in that: The operation processing module includes a third substrate and a third cover plate. The third substrate is provided with an operation processing module component installation cavity. The third cover plate closes the operation processing module component installation cavity. The operation processing module component is electrically connected to the signal conditioning module through the third substrate. The bottom of the third substrate leads out the signal through BGA, LGA or CCGA.

5. The optoelectronic integrated microsystem 3D packaging structure according to claim 1, characterized in that: Two adjacent modules are electrically interconnected via BGA solder balls.

6. The optoelectronic integrated microsystem 3D packaging structure according to claim 1, characterized in that: The projection of the packaging structure parallel to the module arrangement direction is a circle or a regular polygon, and the number of sides of the regular polygon is ≥6.

7. The optoelectronic integrated microsystem 3D packaging structure according to claim 4, characterized in that: The first substrate, the second substrate and the third substrate are multi-layer ceramic substrates.

8. The optoelectronic integrated microsystem 3D packaging structure according to claim 7, characterized in that: The multilayer ceramic substrate is a LTCC substrate or a HTCC substrate.

9. The optoelectronic integrated microsystem 3D packaging structure according to claim 5, characterized in that: Filling glue is filled between two adjacent modules.

10. The method for manufacturing the optoelectronic integrated microsystem 3D packaging structure according to claim 4, characterized in that: The steps include: Step 1: Cut and prepare the first substrate, the second substrate and the third substrate according to the required shapes; Step 2: Weld the metal dam and the outer frame onto the first substrate, mount the photoelectric sensor in the photoelectric detection module components onto the first substrate in the center of the metal dam, install other photoelectric detection module components onto the first substrate between the outer frame and the metal dam, and then weld the first cover plate without the visible light window to the metal dam and the outer frame; metallize the edge of the visible light window and connect the visible light window to the first cover plate through a solder melting process to obtain a photoelectric detection module; Step 3: Assemble the second substrate, the signal conditioning module components and the second cover plate to obtain the signal conditioning module; assemble the third substrate, the operation processing module components and the third cover plate to obtain the operation processing module; Step 4: The photoelectric detection module, signal conditioning module and operation processing module are stacked and packaged from top to bottom, and the layers are interconnected by BGA solder balls. During the welding process, the modules between layers are accurately aligned with the help of an automatic alignment system. After the welding is completed, the stacked layers are fixed with filling glue to obtain the 3D packaging structure of the optoelectronic integrated microsystem.

Images