Array-type white light interferometry device

Abstract

This invention provides an array-type white light interferometry device, comprising: a base and a support mounted on the base; an array-type optical sensing module having a plurality of optical probes, disposed on the support, wherein each optical probe captures an interferometric image of a test object to generate corresponding plurality of raw image data; an air-bearing positioning platform disposed on the base and located below the array-type optical sensing module, for supporting the test object and providing non-contact support during displacement to maintain stable measurement conditions; and a control unit electrically connected to the array-type optical sensing module. The module and the air-bearing positioning platform are used to synchronously control the air-bearing positioning platform to move to the measurement position, and enable the optical probe of the array optical sensing module to perform synchronous image acquisition under a common time reference; a central processing unit is electrically connected to the control unit and has a parallel processing module to perform parallel interferometric calculations on each of the original image data to produce complex surface height information, and to align and stitch the complex surface height information to produce continuous three-dimensional reconstruction data, thereby directly expanding the field of view of a single measurement by multiple times and greatly reducing the number of scans.

Claims

1. An array-type white light interferometric metrology device, comprising: A base; A support bracket is mounted on the base; an array-type optical sensing module is mounted on the support, the array-type optical sensing module has a plurality of optical probes, each of which performs interferometric image capture on a test object to generate corresponding plurality of raw image data; an air-bearing positioning platform is mounted on the base and located below the array-type optical sensing module, the air-bearing positioning platform is used to support the test object and provide non-contact support during displacement to maintain a stable measurement condition; A control unit, electrically connected to the array-type optical sensing module and the air-bearing positioning platform, drives the air-bearing positioning platform to the measurement position and enables the optical probes of the array-type optical sensing module to perform synchronous image acquisition under a common time reference, so that each of the original image data corresponds to a specific spatial position of the object under test; and a central processing unit, electrically connected to the control unit, has a parallel processing module, which performs parallel interferometric calculations on each of the original image data to produce complex surface height information, and the central processing unit aligns and stitches the complex surface height information according to the relative positional relationship of each optical probe and the spatial coordinates of the air-bearing positioning platform to produce continuous three-dimensional reconstruction data; wherein the measurement fields of each optical probe are adjacent or partially overlapping, and the central processing unit performs data correction or compensation based on one of the overlapping areas to improve the accuracy of the three-dimensional reconstruction data.

2. The array-type white light interferometric measurement device as described in claim 1, wherein the plurality of optical probes of the array-type optical sensing module includes four sets of objective lenses arranged in a 2x2 array.

3. The array-type white light interferometric measurement device as described in claim 1, wherein the array-type optical sensing module further includes a positive light source, which is disposed in the optical path of the plurality of optical probes to provide illumination to the surface of the object to be measured.

4. The array-type white light interferometric measuring device as described in claim 1, wherein the air-bearing positioning platform further comprises an air bearing module, a pressure control module and a vacuum pre-compression module.

5. The array-type white light interferometric metering device as described in claim 4, wherein the pressure control module is electrically connected to the control unit for controlling the compressed air supplied to the air bearing module.

6. The array-type white light interferometric metering device as described in claim 4, wherein the vacuum preload module is used to provide an adsorption force to balance the buoyancy generated by the air bearing module, thereby maintaining a constant buoyancy height.

7. The array-type white light interferometric measuring device as described in claim 1 further includes a passive damping component disposed at the bottom of the base to isolate an external vibration.

8. The array-type white light interferometric metrology device as described in claim 7, wherein the passive damping assembly comprises a plurality of anti-vibration pads.

9. The array-type white light interferometric measurement device as described in claim 1, wherein the central processing unit integrates the plurality of raw image data into the three-dimensional reconstruction data with a large field of view based on the real-time spatial coordinates of one of the air-bearing positioning platforms.

10. The array-type white light interferometric measuring device as described in claim 1, wherein the control unit receives a computational feedback signal from one of the central processing units to dynamically adjust the displacement speed of the air-bearing positioning platform.

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