Precise adjustment method of focal plane Dewar CCD (Charge Coupled Device)

Abstract

The invention relates to an assembling and adjusting method of a detector, in particular to a precise assembling and adjusting method of a focal plane Dewar CCD (Charge Coupled Device), and aims to solve the problem that the efficiency is low or the precision is insufficient when a focusing plane Dewar detector is manually assembled. The method comprises the following steps: 1) preparing a Dewar assembly, a detector assembly and an imager measurement assembly; (2) assembling the components; (3) trimming the height of each heat insulation supporting column trimming gasket according to a preset rule by utilizing the cooperation of an image instrument until the distance between each heat insulation supporting column trimming gasket and the window glass and the height error between any two heat insulation supporting column trimming gaskets meet preset requirements, and finally installing the Dewar upper cover plate; 4) adjusting the X-direction position of a detector in the detector assembly; 5) adjusting the Y-direction position of a detector in the detector assembly; and 6) reinforcing and connecting the cold plate and the heat-insulating support column through a heat-insulating support column trimming gasket to finish the precise adjustment of the focal plane Dewar CCD.

Description

Technical Field

[0001] The invention relates to a detector assembly and adjustment method, in particular to a focal plane Dewar CCD precision assembly and adjustment method. Background Art

[0002] The focal plane dewar detector (also called focal plane dewar CCD) is the core equipment for high-precision photoelectric detection technology, which includes dewar components, detector components, refrigeration components and related support components. In a vacuum and low-temperature environment, the dark current and thermal noise of the semiconductor material used in the focal plane dewar detector can be significantly reduced, thereby improving the performance of the detector. Therefore, it is widely used in the field of astronomical observation to capture weak light signals from celestial bodies, such as deep space galaxy detection and exoplanet imaging.

[0003] In actual use, the performance of the focal plane dewar detector is often affected by its installation and adjustment accuracy. The installation and adjustment process includes the installation, adjustment and testing of the detector to ensure that it can achieve the expected performance in actual applications. However, due to the complex internal structure of the focal plane dewar, the installation and adjustment process often requires a lot of manual operation, which is not only inefficient, but also easily leads to insufficient installation and adjustment accuracy. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of low efficiency or insufficient precision in manually adjusting the focal plane Dewar detector, and to provide a precise adjustment method for a focal plane Dewar CCD.

[0005] To achieve the above purpose, the technical solution provided by the present invention is:

[0006] A method for precisely assembling and adjusting a focal plane Dewar CCD is characterized in that it comprises the following steps:

[0007] Step 1: prepare the dewar assembly and detector assembly to be installed and adjusted; prepare and assemble the imager measurement assembly; select the objective lens of the imager in the imager measurement assembly according to the size of the dewar assembly, then install the objective lens and calibrate the accuracy of the imager;

[0008] Step 2, prepare a support fixture and install it to a preset position of the imager measurement assembly, wherein the support fixture includes a horizontal mounting plate and a vertical mounting plate vertically connected to each other; install the Dewar assembly on the horizontal mounting plate of the support fixture; install X thermal insulation support columns in the Dewar assembly, where X≥3;

[0009] Step 3, install the detector assembly on the upper ends of the X thermal insulation support columns inside the Dewar assembly, align the imager probe in the imager measurement assembly with the photosensitive surface of the detector in the detector assembly, wherein a thermal insulation support column trimming gasket is provided between the cold plate of the detector assembly and the upper end of the thermal insulation support column; then, with the cooperation of the imager, trim the height of each thermal insulation support column trimming gasket until the distance and parallelism between the window glass and the photosensitive surface of the detector meet the preset requirements;

[0010] Step 4: Remove the Dewar upper cover plate, and then use the imager to adjust the X-direction position of the detector in the detector assembly until it meets the requirements;

[0011] Step 5: Use the imager to adjust the Y-direction position of the detector in the detector assembly until the requirements are met;

[0012] Step 6: Use filling glue to cut the gaskets of the cold plate and the thermal insulation support column, and reinforce the connection of the thermal insulation support column to complete the precise adjustment of the focusing surface Dewar CCD.

[0013] Further, in step 1, the imager measuring assembly includes a marble platform, a control console connected to the marble platform, a U-shaped Y-direction translation module arranged on the marble platform, an X-direction translation module arranged on the Y-direction translation module, a Z-direction lifting module arranged at the end of the X-direction translation module, and an imager arranged at the lower end of the Z-direction lifting module;

[0014] In step 2, the support fixture is installed to the middle of the marble platform of the imager measurement assembly.

[0015] Furthermore, in step 3, the height of the trimming gasket of each heat insulation support column is trimmed by using an imager until the distance and parallelism between the window glass and the photosensitive surface of the detector meet the preset requirements, specifically:

[0016] Use the imager to select X first measurement points O1, O2...O on the photosensitive surface of the detector. X For height measurement, the number and position of the first measuring point meet the following rules: the polygon formed by X measuring points is similar to the polygon formed by X heat insulation support column trimming gaskets; at the same time, the imager is used to select multiple points O1, O2…O on the window glass of the Dewar assembly that are similar to each first measuring point. X One-to-one corresponding second measurement points P1, P2...P X , and measure the height to calculate K1, K2…K X , where K1 is the distance between point O1 and point P1, K2 is the distance between point O2 and point P2...K X Point O X With point P XThen, the X insulation support column trimming gaskets are cycled to remove, trim, install and debug until K i The value of K meets the preset requirements and any two K i The difference between them is less than 10μm, i=1,2…X.

[0017] Furthermore, step 4 is specifically as follows:

[0018] Remove the Dewar upper cover, use an imager to take points on the four edges of the detector's photosensitive surface, fit the center point O0 of the detector, and establish a spatial rectangular coordinate system O0-XYZ, where the X-axis is parallel to a set of inner side surfaces of the Dewar shell, and the Y-axis is parallel to another set of inner side surfaces of the Dewar shell; define an inner side surface of the Dewar shell parallel to the Y-axis as the first inner side surface, use an imager to take points on the first inner side surface, and fit the installation bottom surface straight line L1, where the line connecting the straight line L1 and the point O0 is the normal of the first inner side surface, and then calculate the distance d1 from the point O0 to the straight line L1; if d1 meets the requirements, proceed to step 5; if d1 does not meet the requirements, adjust the X-direction position of the detector until d1 meets the requirements.

[0019] Furthermore, step 5 is specifically as follows:

[0020] An inner side surface of the Dewar housing adjacent to the first inner side surface is defined as the second inner side surface. An imager is used to sample points on the second inner side surface, and a straight line L2 of the installation bottom surface is fitted, wherein the line connecting the straight line L2 and the point O0 is the normal of the second inner side surface. Then the distance d2 from the point O0 to the straight line L2 is calculated; if d2 meets the requirements, proceed to step 6; if d2 does not meet the requirements, the Y direction position of the detector is adjusted until d2 meets the requirements.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The precision adjustment method of the focal plane Dewar CCD provided by the present invention can achieve higher accuracy in the process of manufacturing the focal plane Dewar CCD. This accuracy can ensure that the size and position of each component of the focal plane Dewar CCD meet the design requirements, thereby improving the performance and stability of the focal plane Dewar CCD;

[0023] 2. The precision adjustment method of the focal plane Dewar CCD provided by the present invention can ensure the consistency of performance of each focal plane Dewar CCD device produced; such consistency is particularly important for large-scale production, and can reduce the device performance changes caused by process differences, and improve the reliability and repeatability of the product;

[0024] 3. The precise adjustment method of the focal plane Dewar CCD provided by the present invention can reduce the cost of subsequent focal plane Dewar CCD testing and correction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flow chart of an embodiment of a method for precise adjustment of a focal plane Dewar CCD of the present invention;

[0026] Figure 2 It is a structural schematic diagram of an imager measuring component, a Dewar component, a detector component and a supporting tooling in an embodiment of a precision adjustment method for a focal plane Dewar CCD of the present invention;

[0027] Figure 3 It is a top view of the Dewar assembly and the detector assembly installed on the supporting fixture in the embodiment of the precision adjustment method of the focal plane Dewar CCD of the present invention;

[0028] Figure 4 It is a cross-sectional view of the Dewar assembly and the detector assembly in the embodiment of the precision adjustment method of the focal plane Dewar CCD of the present invention;

[0029] Figure 5 It is a schematic diagram of using an imager to collect points on the photosensitive surface of the detector 36 in the embodiment of the precision adjustment method of the focal plane Dewar CCD of the present invention;

[0030] Description of reference numerals:

[0031] 1-imager measurement assembly, 11-marble platform, 101-control console, 12-Y translation module, 13-imager, 14-X translation module, 15-Z lifting module; 2-Dewar assembly, 21-window glass, 22-window glass gasket, 23-window glass protection frame, 24-Dewar upper cover, 25-Dewar upper cover cold screen, 26-first Dewar shell insulation pad, 27-Dewar shell cold screen, 28-second Dewar shell insulation pad, 29-Dewar shell, 291-connecting cylinder, 292-refrigeration machine connecting flange; 3-detector assembly, 31-cold plate, 32-detector lower cold head, 33-detector reinforcement frame, 34-circuit board trimming pad, 35-thermal conductive copper strip, 36-detector; 4-support tooling; 51-insulation support column, 52-insulation support column trimming gasket, 53-bolt. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0033] First, the devices required for this embodiment are introduced:

[0034] See also Figure 2The imager measuring assembly 1 includes a marble platform 11, a control console 101 connected to the marble platform 11, a U-shaped Y-direction translation module 12 arranged on the marble platform 11, an X-direction translation module 14 arranged on the Y-direction translation module 12, a Z-direction lifting module 15 arranged at the end of the X-direction translation module 14, and an imager 13 arranged at the lower end of the Z-direction lifting module 15.

[0035] See also Figure 4 The Dewar assembly 2 includes a Dewar shell 29, a Dewar upper cover plate 24 arranged at the upper end of the Dewar shell 29, a Dewar shell cold shield 27 arranged in the Dewar shell 29, a Dewar upper cover cold shield 25 arranged at the upper end of the Dewar shell cold shield 27, and a window glass protection frame 23 embedded in the Dewar upper cover plate 24, and a window glass 21 arranged on the window glass protection frame 23 through a window glass gasket 22; wherein the inner wall of the Dewar shell 29 and the outer wall of the Dewar shell cold shield 27 are connected by a first Dewar shell heat insulation pad 26 arranged at the upper part and a second Dewar shell heat insulation pad 28 arranged at the lower part;

[0036] A connecting cylinder 291 is provided at the lower end of the Dewar shell 29, and a refrigerator connecting flange 292 is provided at one end of the connecting cylinder 291 away from the Dewar shell 29. The connecting cylinder 291 and the refrigerator connecting flange 292 are used to connect with an external refrigerant;

[0037] The four heat-insulating support columns 51 are all connected to the bottom surface of the Dewar housing 29 in the Dewar assembly 2 via bolts 53 .

[0038] See also Figure 3 and Figure 4 The detector assembly 3 includes a cold plate 31 with a through hole in the middle, a detector reinforcement frame 33 set on the upper surface of the cold plate 31 by bolts 53, a detector 36 set in the detector reinforcement frame 33, a detector lower cold head 32 with one end set on the lower surface of the cold plate 31 and contacting the lower surface of the detector 36 through the through hole, a thermal conductive copper strip 35 connected to the other end of the detector lower cold head 32, and a plurality of circuit board trimming pads 34 set between the cold plate 31 and the PCD board of the detector 36.

[0039] The precision adjustment method of focal plane Dewar CCD, the flow chart of which can be found in Figure 1 , including the following steps:

[0040] Step 1, prepare the Dewar assembly 2 and the detector assembly 3 to be installed and adjusted; prepare and assemble the imager measuring assembly 1; select the objective lens of the imager 13 in the imager measuring assembly 1 according to the size of the Dewar assembly 2, then install the objective lens, and calibrate the accuracy of the imager 13;

[0041] Step 2, prepare a support fixture 4 and install it to a preset position of the imager measuring assembly 1, the support fixture 4 comprising a horizontal mounting plate and a vertical mounting plate vertically connected to each other; install the Dewar assembly 2 on the horizontal mounting plate of the support fixture 4; install X thermal insulation support columns 51 in the Dewar assembly 2, X≥3;

[0042] Step 3: Install the detector assembly 3 on the upper ends of the X thermal insulation support columns 51 inside the Dewar assembly 2, and align the imager 13 probe in the imager measurement assembly 1 with the photosensitive surface of the detector 36 in the detector assembly 3, wherein a thermal insulation support column trimming gasket 52 is provided between the cold plate 31 of the detector assembly 3 and the upper ends of the thermal insulation support columns 51; then use the imager 13 to select X first measurement points O1, O2, ..., on the photosensitive surface of the detector 36. X The height measurement is performed, and the number and position of the first measuring points meet the following rules: the polygon formed by the X measuring points is similar to the polygon formed by the X heat insulation support column trimming gaskets 52; at the same time, the imager 13 is used to select multiple points O1, O2, ... O on the window glass 21 of the Dewar assembly 2 that are similar to each of the first measuring points. X One-to-one corresponding second measurement points P1, P2...P X , and measure the height to calculate K1, K2…K X , where K1 is the distance between point O1 and point P1, K2 is the distance between point O2 and point P2...K X Point O X With point P X Then X insulation support column trimming gasket 52 cycles to remove the trimming and installation and debugging operations until K i The value of K meets the preset requirements and any two K i The difference between them is less than 10 μm, i = 1, 2 ... X. In this step, the distance and parallelism between the window glass 21 and the detector sensing surface 36 can be controlled by trimming the thickness of the gasket 52 of the four heat-insulating support columns, which is easy to operate and safe.

[0043] Step 4, remove the Dewar upper cover plate 24, use the imager 13 to sample points on the four edges of the photosensitive surface of the detector 36, fit the center point O0 of the detector 36, and establish a spatial rectangular coordinate system O0-XYZ, wherein the X-axis is parallel to a set of inner side surfaces of the Dewar shell 29, and the Y-axis is parallel to another set of inner side surfaces of the Dewar shell 29; define an inner side surface of the Dewar shell 29 parallel to the Y-axis as the first inner side surface, use the imager 13 to sample points on the first inner side surface, and fit the installation bottom surface straight line L1, wherein the line connecting the straight line L1 and the point O0 is the normal of the first inner side surface, and then calculate the distance d1 from the point O0 to the straight line L1; if d1 meets the requirements, proceed to step 5; if d1 does not meet the requirements, adjust the X-direction position of the detector 36 until d1 meets the requirements;

[0044] Step 5, define an inner side surface of the Dewar housing 29 adjacent to the first inner side surface as the second inner side surface, use the imager 13 to collect points on the second inner side surface, and fit the installation bottom surface straight line L2, where the line connecting the straight line L2 and the point O0 is the normal of the second inner side surface, and then calculate the distance d2 from the point O0 to the straight line L2; if d2 meets the requirements, proceed to step 6; if d2 does not meet the requirements, adjust the Y direction position of the detector 36 until d2 meets the requirements. Steps 4 and 5 use the imager 13 to accurately measure the end face of the structure, and characterize the relative spatial position of the detector 36 and the Dewar housing 29 by measuring the distance from the point to the straight line, thereby realizing the posture control of the detector 36 in the direction perpendicular to the optical axis, which is highly practical.

[0045] Step 6: Use filling glue to reinforce the connection between the cold plate 31 and the heat-insulating support column 51 through the heat-insulating support column trimmed gasket 52 to complete the precise adjustment of the focus surface Dewar CCD.

Claims

1. A method for precise adjustment of a focal plane Dewar CCD, characterized in that: The following steps are involved: Step 1, prepare the dewar assembly (2) and the detector assembly (3) to be installed and adjusted; prepare and assemble the imager measuring assembly (1); select the objective lens of the imager (13) in the imager measuring assembly (1) according to the size of the dewar assembly (2), then install the objective lens, and calibrate the accuracy of the imager (13); Step 2, prepare a support fixture (4) and install it to a preset position of the imager measurement component (1), wherein the support fixture (4) comprises a horizontal mounting plate and a vertical mounting plate vertically connected to each other; install the Dewar component (2) on the horizontal mounting plate of the support fixture (4); install X heat-insulating support columns (51) in the Dewar component (2), where X≥3; Step 3, the detector assembly (3) is installed on the upper ends of the X thermal insulation support columns (51) inside the dewar assembly (2), and the imager (13) probe in the imager measuring assembly (1) is aligned with the photosensitive surface of the detector (36) in the detector assembly (3), wherein a thermal insulation support column trimming gasket (52) is provided between the cold plate (31) of the detector assembly (3) and the upper end of the thermal insulation support column (51); then, the height of each thermal insulation support column trimming gasket (52) is trimmed by using the imager (13) until the distance and parallelism between the window glass (21) and the photosensitive surface of the detector (36) meet the preset requirements; Step 4, remove the Dewar upper cover plate (24), and then use the imager (13) to adjust the X-direction position of the detector (36) in the detector assembly (3) until the requirement is met; Step 5: Using the imager (13), adjust the Y-direction position of the detector (36) in the detector assembly (3) until the requirement is met; Step 6: Use filling glue to reinforce the connection between the cold plate (31), the heat insulation support column trimming gasket (52), and the heat insulation support column (51), and complete the precise assembly and adjustment of the focus surface Dewar CCD.

2. The precision adjustment method of the focal plane Dewar CCD according to claim 1, characterized in that: In step 1, the imager measuring assembly (1) comprises a marble platform (11), a control console (101) connected to the marble platform (11), a U-shaped Y-direction translation module (12) arranged on the marble platform (11), an X-direction translation module (14) arranged on the Y-direction translation module (12), a Z-direction lifting module (15) arranged at the end of the X-direction translation module (14), and an imager (13) arranged at the lower end of the Z-direction lifting module (15); In step 2, the supporting fixture (4) is mounted to the middle of the marble platform (11) of the imager measuring assembly (1).

3. The method for precise adjustment of focal plane Dewar CCD according to claim 2, characterized in that: In step 3, the height of each heat insulation support column trimming gasket (52) is trimmed by using the imager (13) until the distance and parallelism between the window glass (21) and the photosensitive surface of the detector (36) meet the preset requirements, specifically: Select X first measuring points O1, O2, ..., on the photosensitive surface of the detector (36) by using an imager (13); X Height measurement is performed, and the number and position of the first measuring points meet the following rules: a polygon formed by the X measuring points is similar to a polygon formed by the X heat insulation support column trimming gaskets (52); and an imager (13) is used to select a plurality of first measuring points O1, O2, ... O2 on the window glass (21) of the Dewar assembly (2). X One-to-one corresponding second measurement points P1, P2...P X , and measure the height to calculate K1, K2…K X , where K1 is the distance between point O1 and point P1, K2 is the distance between point O2 and point P2...K X Point O X With point P X Then X insulation support column trimming gasket (52) cycle to remove the trimming and installation and debugging operations until K i The value of K meets the preset requirements and any two K i The difference between them is less than 10μm, i=1,2…X.

4. The precision adjustment method of the focal plane Dewar CCD according to claim 3, characterized in that: Step 4 is as follows: The Dewar upper cover plate (24) is removed, and the four edges of the photosensitive surface of the detector (36) are sampled using an imager (13), the center point O0 of the detector (36) is fitted, and a spatial rectangular coordinate system O0-XYZ is established, wherein the X-axis is parallel to a group of inner side surfaces of the Dewar shell (29), and the Y-axis is parallel to another group of inner side surfaces of the Dewar shell (29); an inner side surface of the Dewar shell (29) parallel to the Y-axis is defined as a first inner side surface, and the imager (13) is used to sample points on the first inner side surface, and a straight line L1 of the installation bottom surface is fitted, wherein the line connecting the straight line L1 and the point O0 is the normal line of the first inner side surface, and then the distance d1 from the point O0 to the straight line L1 is calculated; if d1 meets the requirements, step 5 is performed; if d1 does not meet the requirements, the X-direction position of the detector (36) is adjusted until d1 meets the requirements.

5. The method for precise adjustment of focal plane Dewar CCD according to claim 4, characterized in that: Step 5 is as follows: An inner side surface of the dewar housing (29) adjacent to the first inner side surface is defined as a second inner side surface, and points are collected on the second inner side surface using an imager (13), and a straight line L2 of the installation bottom surface is fitted, wherein a line connecting the straight line L2 and the point O0 is a normal line of the second inner side surface, and then a distance d2 from the point O0 to the straight line L2 is calculated; if d2 meets the requirement, step 6 is performed; if d2 does not meet the requirement, the Y direction position of the detector (36) is adjusted until d2 meets the requirement.

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