Automatic mounting method for infrared detector chip component

Abstract

The invention discloses an automatic mounting method for an infrared detector chip component, which controls automatic mounting equipment to automatically mount the infrared detector chip component and a cold table through a design program, so that the chip bonding process is simplified, and the chip bonding efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of photoelectric detection technology, and in particular to an automatic mounting method for infrared detector chip components. Background Technology

[0002] The infrared detector assembly consists of a detector chip, micro Dewars, and a cooler. Each micro Dewar is individually packaged from a cold finger, structural components, a frame, the detector chip, and optical parts. The structure formed by bonding the chip to the frame, or the chip to the frame and structural components, is called the chip assembly. The chip assembly is bonded to the cold finger and cold stage, requiring correct bonding orientation and the chip assembly's center to be centered on the cold stage. After bonding, the X and Y direction bonding deviations must be ≤10μm, and the Z direction deviation must be ≤50μm. The bonding accuracy between the chip assembly and the cold stage plays a crucial role in the imaging of the infrared detector assembly.

[0003] This process is typically performed by technicians under a tool microscope. First, the Dewar semi-finished product with adhesive applied to the cold stage is fixed onto a fixture. Then, the chip component is placed on the surface of the cold stage for bonding. During bonding, the chip needs to be continuously fine-tuned under the microscope to move it to the accurate position. After bonding, another technician checks the post-bonding coordinates. Finally, a heating cover is used for pre-curing, which takes 3 hours. Every hour, the chip needs to be manually checked and adjusted to the standard position. This may be because the force on the bonding interface is uneven during manual bonding, causing the adhesive to slip at the micron level when the viscosity is low during the pre-curing process. This requires re-bonding, thus reducing bonding efficiency. Summary of the Invention

[0004] This invention provides an automatic mounting method for infrared detector chip components to solve the problems of cumbersome and inefficient chip bonding processes in existing methods.

[0005] This invention provides an automatic mounting method for infrared detector chip components, the method comprising: The Dewar semi-finished product is fixed onto the placement table of the automatic placement equipment using the fixing fixture of the automatic placement equipment. The center position of the chip component and the cold stage is identified by the vision recognition system. The chip component is picked up by the chip nozzle, and the chip component is aligned with the center position of the cold stage before being bonded. Heated nitrogen gas is blown into the bottom of the cold stage through an air blowing tube to heat the bonding surface of the cold stage, thereby curing the chip components onto the cold stage.

[0006] Optionally, the method further includes: designing different types of chip nozzles and Dewar fixtures to mount different types of chip components to a cold stage on an automated placement machine.

[0007] Optionally, a pressure sensor can be used to detect the pressure between the chip components on the placement stage and the cold stage to ensure that the adhesive is subjected to consistent force during chip component placement.

[0008] Optionally, a placement pressure is set, and the pressure between the chip component and the cold stage on the placement stage is controlled to remain at the placement pressure.

[0009] Optionally, the step of identifying the center position of the chip component and the cold stage using a visual recognition system, aligning the chip component with the center position of the cold stage, and then bonding them includes: The camera of the automatic placement equipment identifies the cold stage, selects three points on the edge of the cold stage, and calculates and determines the center of the cold stage based on the selected three points; The camera identifies the placement angle and center position of the chip component; The automatic chip placement equipment uses a pick-up nozzle to extract chip components and then bonds them to the cold plate.

[0010] Optionally, before the step of identifying the center position of the chip component and the cold stage using a visual recognition system, aligning the chip component with the center position of the cold stage, and then bonding them, the method further includes: The automatic placement equipment uses a suction head to pick up a height measuring nozzle, moves it above the cold stage, and uses the height measuring nozzle to measure the flatness of the cold stage.

[0011] Optionally, if the flatness is <50μm, the flatness of the cold stage is deemed acceptable.

[0012] Optionally, after the chip components are cured onto the cold stage, the method further includes: After the chip components and the cold stage are cured, a post-placement coordinate inspection is performed. Once the coordinate inspection is passed, the placement is considered complete.

[0013] Optionally, if the X-axis offset of the attached chip component and the cold stage is ≤10μm and the Y-axis offset is ≤10μm, then the mounting is deemed qualified.

[0014] Optionally, the chip component is a chip and a frame, or a structure formed by bonding the chip, the frame, and structural components together.

[0015] The beneficial effects of this invention are as follows: This invention uses a designed program to control an automated placement device to automatically mount infrared detector chip components onto a cold stage, thereby simplifying the chip bonding process and improving chip bonding efficiency.

[0016] The above description is merely an overview of the technical method of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic diagram of the Dewar semi-finished product and chip components provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the Dewar fixing and positioning clamp and heating device provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a chip suction nozzle provided in an embodiment of the present invention; Figure 4 This is a flowchart illustrating the bonding process between a chip component and a cold stage, as provided in an embodiment of the present invention. Figure 5 The image shows the actual effect of automated chip component placement provided in the embodiment of the present invention.

[0018] Figure descriptions: 1. Chip component; 2. Cold stage; 3. Fixture; 4. Air tube; 5. Chip suction nozzle. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of the invention.

[0020] Typically, the mounting process of infrared detector chip components onto a cold-finger stage is performed by technicians under a tool microscope. They manually adjust the chip position to the precise location, pressing down on the chip to prevent adhesive overflow. Finally, a heating cover is used for pre-curing, which takes 3 hours, requiring manual inspection and adjustment of the chip to the standard position every hour. This manual bonding process is tedious, requiring at least two technicians to bond one component, and occupying a tool microscope for at least 4 hours per component. Furthermore, uneven pressure during placement can result in Z-axis deviations exceeding 50μm, necessitating re-bonding and further reducing bonding efficiency. Additionally, since different technicians perform this process for all component chip bonding, inconsistent and uneven adhesive stress at the bonding surfaces can lead to unstable bonding interface quality after curing. Therefore, this process is primarily performed manually by experienced technicians. Conventional infrared detector chip bonding is inefficient, time-consuming, and labor-intensive, and cannot guarantee the stability and consistency of the final product quality.

[0021] To address the above problems, embodiments of the present invention provide an automatic mounting method for infrared detector chip components, see [link to relevant documentation]. Figure 1 The method includes: S101. Use the fixing clamp 3 of the automatic placement equipment to fix the Dewar semi-finished product onto the placement table of the automatic placement equipment. Use the vision recognition system to identify the center position of the chip component 1 and the cold table 2. Then pick up the chip component 1 through the chip nozzle 5, align the center position of the chip component 1 with the center position of the cold table 2, and then bond them together. In specific implementation, embodiments of the present invention may involve designing different models of chip nozzles 5 and Dewar fixing clamps 3 to mount different chip components 1 and cold stage 2 on an automatic placement machine.

[0022] That is, the chip suction nozzle 5 and the fixing clamp 3 in the embodiments of the present invention can be designed according to the chip and Dewar structure to be bonded.

[0023] Furthermore, during the bonding process, this embodiment of the invention can also use a pressure sensor to detect the pressure between the chip component 1 and the cold stage 2 on the chip mounting platform, so as to ensure that the adhesive on the chip component 1 is subjected to consistent force during mounting.

[0024] In practical implementation, pressure sensors can be installed at different positions on the placement stage to detect the pressure at different locations between the chip component 1 and the cold stage 2. Alternatively, the pressure sensors can be used to directly obtain the pressure at different locations on the cold stage 2. Those skilled in the art can configure the sensors according to actual needs, and this invention does not impose specific limitations on this.

[0025] It can be understood that the present invention ensures the success rate of chip placement by pre-setting the placement pressure and controlling the pressure between the chip component 1 and the cold stage 2 on the placement stage to always maintain the placement pressure.

[0026] S102. Heated nitrogen gas is blown into the bottom of the cold stage 2 through the air blowing pipe 4 to heat the bonding surface of the cold stage 2, so as to cure the chip component 1 onto the cold stage 2, and obtain the structure 6 after the chip component is connected to the cold stage.

[0027] In other words, in this embodiment of the invention, the pre-curing of the adhesive at the mounting stage is achieved by heating with nitrogen at the bottom of the cold stage: the air blowing pipe 4 at the mounting stage blows heated nitrogen gas to the bottom of the cold stage 2 to heat the bonding surface of the cold stage 2, the structure of which is shown in [see figure]. Figure 2 .

[0028] As can be seen from the above, the method of the present invention enables the entire bonding process to be operated by only one process engineer on a computer with a pre-programmed process flow. The operation process is simple and saves manpower, while ensuring the bonding quality of chip component 1 and improving bonding efficiency.

[0029] Furthermore, in a specific implementation, the embodiment of the present invention uses the camera of the automatic placement equipment to identify the cold stage 2, select three points on the edge of the cold stage 2, calculate and determine the center of the cold stage 2 based on the selected three points; then, the camera identifies the placement angle and center position of the chip component 1; and the suction head of the automatic placement equipment picks up the chip nozzle 5 and picks up the chip component 1 to bond the chip component 1 to the cold stage 2.

[0030] Specifically, in this embodiment of the invention, the suction head of the automatic placement equipment picks up the height measuring nozzle, moves it above the cold stage 2, and measures the flatness of the cold stage 2 using the height measuring nozzle. For example, if the flatness is <50μm, the flatness of the cold stage 2 is determined to be acceptable.

[0031] Furthermore, after the chip component 1 is cured onto the cold stage 2 as described in this embodiment of the invention, the method further includes: performing post-placement coordinate inspection on the cured chip component 1 and the cold stage 2; when the coordinate inspection passes, the placement is determined to be complete. Specifically, the placement is considered qualified when the X-axis offset of the placed chip component 1 and the cold stage 2 is ≤10μm and the Y-axis offset is ≤10μm.

[0032] It should be noted that the chip component 1 described in the embodiments of the present invention is a chip and a frame, or a structure in which the chip, the frame and structural components are bonded together.

[0033] Practice has proven that the infrared detector chip component 1 and the cold finger automated mounting method of this invention have at least the following beneficial effects: This invention provides an automated mounting method for a detector chip component 1 and a cold stage 2. By designing chip nozzles 5 and fixing fixtures 3 corresponding to different products, different product chip components 1 and cold stage 2 can be mounted on a single mounting machine. Automated mounting of the infrared detector chip component 1 and cold stage 2 can be achieved through equipment programming. By using a pressure sensor and setting the mounting pressure, consistent stress on the adhesive during chip component 1 mounting can be ensured. Adding a nitrogen heating device to heat and cure the adhesive on the surface of the cold stage 2 can greatly improve pre-curing efficiency. This method can guarantee the stability and consistency of product quality after mounting the infrared detector chip component 1 and cold stage 2, while improving mounting efficiency.

[0034] In practical implementation, the method of this invention mainly utilizes an automated placement device, a pick-and-place nozzle for the chip component 1, a fixing fixture 3, and nitrogen heating at the bottom of the cooling stage 2. The principle of automated placement is as follows: the chip component 1 is placed on the material stage; the Dewar semi-finished product is fixed to the placement stage using a fixture; a vision recognition system automatically identifies the center position of the cooling stage 2 and the chip component 1; the pick-and-place nozzle 5 automatically picks up the chip component 1 and places it at the center of the cooling stage 2; and nitrogen heating is used to pre-cure the adhesive. The detailed steps of the automated placement process are as follows: The pre-applied adhesive-coated Dewar semi-finished product is fixed onto the corresponding fixture on the placement stage, and chip component 1 is placed on the material stage. The camera identifies the cold stage 2, selects three points on the edge of the cold stage 2, and automatically calculates and determines the center of the cold stage 2. The suction head picks up the height measuring nozzle, moves it above the cold stage 2, and measures the flatness of the cold stage 2. Flatness < 50μm is considered acceptable, and the suction head is returned to the height measuring nozzle. The camera identifies the placement angle and center position of chip component 1. The suction head picks up the chip nozzle 5, then picks up chip component 1, and bonds chip component 1 to the cold stage 2. After chip component 1 is mounted on the cold stage 2, the adhesive is pre-cured. After pre-curing, a post-mounting coordinate inspection is performed. The acceptable inspection standard is X-axis offset ≤ 10μm and Y-axis offset ≤ 10μm. This automated mounting process for infrared detector chip component 1 ensures the consistency and stability of the product quality after bonding and is conducive to further improving the mounting efficiency of infrared detector chip component 1.

[0035] The following will combine Figures 1-5 The method described in the embodiments of the present invention will be explained and illustrated in detail through a specific example: like Figure 1 As shown, in this embodiment of the invention, the chip component 1 is mounted onto the cold finger cold stage 2 of the Dewar semi-finished product using a fully automated placement table. The automated placement method is described in [link to documentation]. Figure 4 The detailed steps are as follows: Fix the pre-applied adhesive-coated Dewar semi-finished product onto the corresponding fixture 3 at the mounting table, see Figure 2Different models of Dewar semi-finished products correspond to corresponding models of fixtures; place chip component 1 on the material stage, and ensure that the flatness of the material stage and the placement stage is within 10μm.

[0036] Visually identify cold table 2, select three points on the edge of cold table 2, and automatically calculate and determine the center of cold table 2.

[0037] The suction head picks up the height measuring nozzle and moves it above the cold stage 2. The flatness of the cold stage 2 is measured. If the flatness is <50μm, it is considered qualified. The suction head is then placed back into the height measuring nozzle, and the next step is performed. If the flatness is not qualified, the process is terminated, and a suitable Dewar semi-finished product cold finger needs to be replaced and the process restarted.

[0038] After the flatness measurement of the cold stage 2 is qualified, the two-point method is used to identify the placement angle of the chip component 1. If the identified angle is ≥0.02°, the material stage will automatically rotate until the placement angle of the chip component 1 is <0.02°.

[0039] After the chip component 1 is placed at the correct angle, the center position of the chip component 1 is identified using the four-point method. The suction head then picks up the chip from the suction nozzle 5. (See...) Figure 3 Place chip component 1 onto the center of cold stage 2 (the suction head applies 130g of pressure to chip component 1) to ensure that the adhesive layer thickness is consistent after bonding, approximately 0.04mm.

[0040] After the chip component 1 is attached to the cold stage 2, the suction head is removed to pre-cure the adhesive. The curing temperature is 110℃ and the curing time is 40 minutes.

[0041] After pre-curing, post-application coordinate inspection is performed. The inspection pass criteria are X≤10μm, Y≤10μm, and deflection angle≤0.05°.

[0042] The finished product after automated placement is shown below. Figure 5 By employing the above-described automated mounting scheme for infrared detector chip component 1, along with related tooling and nitrogen heating, not only can the bonding accuracy of chip component 1 be guaranteed and bonding efficiency improved, but the bonding reliability of chip component 1 can also be enhanced, ensuring consistent product quality. This invention is applicable to the bonding of all models of chip component 1 to cold fingers in infrared detector assembly packaging.

[0043] In other words, this invention enables automated mounting of the infrared detector chip component 1 to the cold stage 2. The center of the chip component 1 is located at the center of the cold stage 2, and the mounting accuracy is superior to that of manual bonding. The automated mounting accuracy is: X offset ≤ 10μm, Y offset ≤ 10μm. Compared to the manual mounting accuracy (X offset ≤ 10μm, Y offset ≤ 10μm), this invention achieves higher accuracy, at least reaching the highest accuracy of manual mounting. Furthermore, the mounting of the detector chip component 1 in this embodiment of the invention utilizes a designed fixing fixture 3 and chip suction head, enabling mounting processes of chip components 1 and cold stage 2 for various products. Moreover, in the mounting method of the detector chip component 1 in this embodiment of the invention, the nitrogen heating method at the bottom of the cold stage 2, with heated nitrogen directly blown from the air pipe 4 to the bottom of the cold stage 2, results in high heating efficiency of the bonding surface. Traditional heating methods use radiant heating from a heating cover, which has low heating efficiency of the bonding surface. The pre-curing time is shortened from 4 hours manually to approximately 40 minutes, increasing the pre-curing efficiency by approximately 6 times. Furthermore, by setting the bonding pressure using the pressure sensor at the suction head, this invention ensures consistent pressure at the bonding interface of each component during bonding, thereby guaranteeing the consistency and stability of the product quality after bonding.

[0044] Although preferred embodiments of the invention have been disclosed for illustrative purposes, those skilled in the art will recognize that various modifications, additions, and substitutions are possible, and therefore the scope of the invention should not be limited to the embodiments described above.

Claims

1. An automatic mounting method for infrared detector chip components, characterized in that, The method includes: The Dewar semi-finished product is fixed onto the placement table of the automatic placement equipment using the fixing clamps of the automatic placement equipment. The center position of the chip component and the cold stage is identified by the vision recognition system. The chip component is picked up by the chip nozzle, and the chip component is aligned with the center position of the cold stage before being bonded. Heated nitrogen gas is blown into the bottom of the cold stage through an air blowing tube to heat the bonding surface of the cold stage, thereby curing the chip components onto the cold stage.

2. The method according to claim 1, characterized in that, The method further includes: By designing different models of chip nozzles and Dewar fixtures, different models of chip components can be mounted on a cold stage on an automated placement machine.

3. The method according to claim 1, characterized in that, Pressure sensors are used to detect the pressure between the chip components on the placement stage and the cold stage to ensure that the adhesive is subjected to consistent force during chip component placement.

4. The method according to claim 3, characterized in that, Set the placement pressure and control the pressure between the chip component and the cold stage on the placement stage to maintain the placement pressure.

5. The method according to any one of claims 1-4, characterized in that, The step of identifying the center position of the chip component and the cold stage using a visual recognition system, aligning the chip component with the center position of the cold stage, and then bonding them includes: The camera of the automatic placement equipment identifies the center position of the cold stage, selects multiple points on the edge of the cold stage, and calculates and determines the center of the cold stage based on the selected points. The camera identifies the placement angle and center position of the chip component; The automatic chip placement equipment uses a pick-up nozzle to extract chip components and then bonds them to the cold plate.

6. The method according to claim 5, characterized in that, Before the process of identifying the center positions of the chip component and the cold stage using a visual recognition system, aligning the chip component with the center position of the cold stage, and then bonding them, the method further includes: The automatic placement equipment uses a suction head to pick up a height measuring nozzle, moves it above the cold stage, and uses the height measuring nozzle to measure the flatness of the cold stage.

7. The method according to claim 6, characterized in that, If the flatness is less than 50 μm, the flatness of the cold stage is considered to be acceptable.

8. The method according to any one of claims 1-4, characterized in that, After the chip components are cured onto the cold stage, the method further includes: After the chip components and the cold stage are cured, a post-placement coordinate inspection is performed. Once the coordinate inspection is passed, the placement is considered complete.

9. The method according to claim 8, characterized in that, If the X-axis offset of the mounted chip component and the cold stage is ≤10μm and the Y-axis offset is ≤10μm, then the mounting is considered qualified.

10. The method according to any one of claims 1-4, characterized in that, The chip component is either a chip and a frame, or a structure formed by bonding the chip, frame, and structural components together.

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