Area density full control device

Abstract

Area density full control device comprising several scanning units (1) laid out along a winding direction of the test specimen, wherein all scanning units (1) are arranged in the same straight line along the width direction of the test specimen and every two scanning units (1) adjacent along the width direction of the test specimen are laid out in different straight lines, wherein the width of the test specimen is covered by the effective test widths of the scanning units (1).

Description

TECHNOLOGY AREA

[0001] The invention relates to the technology for area density control, in particular to an area density full control device. BACKGROUND

[0002] In current applications, areal density control in industries such as lithium-ion battery wafers, film, and foil has evolved from sampling to comprehensive inspection. The core concept for achieving comprehensive inspection is based on a line scanning method. A strip-shaped light spot is generated to cover the entire width of the test specimen, and the resulting scans are received by a line array detector. A correlation is then established between the signal-based measurement and the actual areal density according to a standardized specification. Finally, continuous inspection is performed along the winding direction of the test specimen. This enables comprehensive line scanning inspection of a wide test specimen.

[0003] For area density control using X-rays, three sources are available in the prior art for generating a striped light spot: X-ray beam source, diffuse X-ray source, and distributed X-ray source. The following disadvantages exist in this regard: (1) The X-ray source in conjunction with a grating collimator in front of a line array detector represents an ideal way to achieve full control, but is still quite far from commercial use; (2) Although the diffuse X-ray source produces a striped light spot on a wide test specimen due to a single high-power X-ray source and the limitations of a collimator, it has the following disadvantages: with a greater width of the test specimen, the oblique angle of incidence at the edge of the test specimen will also be greater, which is detrimental for areal density profile control at the edge. In addition, the radiation at the center is quite significantly different from the radiation at the edge, so that the reproducibility of areal density control at the edge remains very different from that at the center; (3) The distributed X-ray source focuses on a line to combine the fan-shaped beam at the test specimen during illumination. In this case, beam overlap will occur at the line array detector after the fan-shaped beam has been combined, since the test specimen is still a considerable distance from the line array detector. This beam overlap impairs the correctness and accuracy of the areal density profile control. DESCRIPTION OF THE INVENTION

[0004] The invention aims to provide a full area density control device in order to eliminate the aforementioned conventional shortcomings.

[0005] To solve the problem, an area density full control device is provided, which comprises several scanning units laid out along a winding direction of the test specimen, wherein all scanning units are arranged in the same straight line along the width direction of the test specimen and every two scanning units adjacent along the width direction of the test specimen are laid out in different straight lines, wherein the width of the test specimen is covered by the effective test widths of the scanning units.

[0006] It is further specified that the effective test widths of the individual scanning units are connected one after the other along the width direction of the test object, whereby the sum of the effective test widths of all scanning units is greater than the width of the test object to be measured.

[0007] It is further elaborated that all scanning units are uniformly constructed in the same way and each scanning unit comprises a beam source, a collimator attached to the bottom of the beam source and a line array detector located just below the collimator, wherein the collimator converts the beam emitted by the beam source into a fan-shaped beam which shines onto the line array detector and then produces a strip-shaped spot of light, thereby covering the length of the line array detector, the line array detector receiving the radiation from the beam source.

[0008] It is further elaborated that several beam sources and several collimators are fixed in one housing, while several line array detectors are all mounted in another housing, with a gap provided between the two housings to accommodate the through-body test specimen, the plane of the test specimen remaining parallel to the height planes of the beam sources and the line array detectors.

[0009] It is further elaborated that each beam source interacts with a complementary line array detector, so that no beam source throws its fan-shaped beam onto another line array detector.

[0010] The areal density full control device according to the invention can, compared to the prior art, It produces a striped light spot for line-by-line full inspection and has the following advantages: (1) The foci of the beam source are offset from each other along two straight lines to eliminate the effect of any beam overlap on the correctness and accuracy of the area density profile control; (2) The width of the test specimen is flexibly adjusted by the effective test width of the individual scanning unit on the test specimen and the connection of the adjacent scanning units to achieve a full area density check on a test specimen of any width; (3) All performance characteristics of the area density control remain relatively identical because the beam angle of each scanning unit is smaller, large-angle oblique illumination is avoided, and the radiation difference between different points in a strip-shaped light spot is reduced. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows a perspective view of the embodiment according to the invention. Fig. Figure 2 shows a view of a scanning unit according to the invention. Reference symbol list:

[0011] 1. Scanning unit; 101. Beam source; 102. Collimator; 103. Line array detector DETAILED DESCRIPTION OF EXAMPLES OF EXECUTION

[0012] The preferred embodiments are described below with reference to the drawings. Unless expressly stated otherwise, the terms "installation," "connecting," and "linking" in this description are to be understood in a broad sense; for example, they may refer to a fixed connection, a detachable connection, or an integral body; or to a mechanical or electrical connection; or to a direct connection or an indirect connection via an intermediary; or to internal communication or an interaction between two elements. Those skilled in the art will be able to understand the inventive meanings of the foregoing terms depending on the context.Furthermore, it should be noted that the terms used in the description of the invention, such as "top," "bottom," "front," "back," "left," "right," "top," "bottom," "inside," and "outside," refer to the orientations or positional relationships shown in the accompanying figures and ensure easy comprehension of the embodiments according to the invention. They do not constitute instructions for actual positioning or practical directions of operation of the components. In this context, the aforementioned positional terms do not represent any limitations of the embodiment according to the invention.

[0013] During areal density full inspection, the strip-shaped test specimen continuously passes between the beam source and the line array detector. The beam source irradiates downwards, and the line array detector receives the beam passing through the test specimen to perform an areal density full inspection. The winding direction is considered the displacement direction of the test specimen, and the width direction is considered the width direction of the test specimen.

[0014] With reference to Fig. 1 and Fig. 2. The areal density full control device according to the invention comprises several scanning units 1 arranged along a winding direction of the test specimen, wherein all scanning units 1 are arranged in the same straight line along the width direction of the test specimen, and every two scanning units 1 adjacent along the width direction of the test specimen are arranged in different straight lines, wherein the width of the test specimen is covered by the effective test widths of the scanning units 1. In the present embodiment, a total of two scanning units 1 are provided, which are spaced apart from each other in two straight lines along the width direction of the test specimen in order to exclude any interference between the two scanning units 1.

[0015] All scanning units 1 are identically constructed. Each scanning unit 1 comprises a beam source 101, a collimator 102 attached to the base of the beam source 101, and a line array detector 103 located vertically below the collimator 102. The collimator 102 converts the beam emitted by the beam source 101 into a fan-shaped beam, which illuminates the line array detector 103 and then produces a strip-shaped spot of light, thus covering the length of the line array detector 103. The line array detector (103) serves to receive the radiation from the beam source (101).

[0016] Several beam sources 101 and several collimators 102 are fixed in one housing, while several line array detectors 103 are all mounted in another housing, with a gap provided between the two housings to accommodate the through-body test specimen, the plane of the test specimen remaining parallel to the height planes of the beam sources 101 and the line array detectors 103.

[0017] The effective test widths of the individual scanning units 1 are connected sequentially along the width direction of the test specimen, with the sum of the effective test widths of all scanning units 1 being greater than the width of the test specimen to be measured. In the practical inspection process, the test specimen passes between the beam source 101 and the line array detector 103, with a height difference existing between the test specimen and the line array detector 103 (see Fig.2) The beam length onto the test object differs from the beam length onto the line array detector 103 because the fan-shaped beam has a certain magnification effect. The magnification ratio is M = L2 / L1, where the effective test width of the individual scanning unit 1 on the test object (the effective test width corresponds to the actual test width of the line array detector 103 to be measured under a certain geometric relationship) is denoted as w, the distance from the focus of the beam source 101 to the test object is denoted as L1, and the distance from the focus of the beam source 101 to the line array detector 103 is denoted as L2. The line array detector 103 can be of a conventional design and will not be described in detail here.In the present embodiment, n pixel detectors are arranged along the width direction of the test object, such that the effective test width w = (n*a) / M corresponds to where the length of a pixel detector is denoted as a, and the length of the line array detector 103 of the individual scanning unit 1 is denoted as n*a.

[0018] Each beam source 101 interacts with a complementary line array detector 103 such that no beam source 101 throws its fan-shaped beam onto any other line array detector 103.

[0019] In the present embodiment, the multiple beam sources 101 and the multiple line array detectors 103 are each uniformly dimensioned and located on the same vertical plane. The individual effective scan widths of the scanning units 1 are also the same.

[0020] In another embodiment, scanning units 1 can be dimensioned differently as required in order to achieve the start-end-point coupling of the effective test widths of the two adjacent scanning units 1.

[0021] In another embodiment, the individual beam sources 101 have different height positions, while the individual line array detectors 103 are at the same height. Since the beam emitted by the beam source 101 is a fan-shaped beam, the light spot (test width of the scanning unit 1) on the test object can be adjusted by adjusting the height position or the beam angle in conjunction with the corresponding line array detector 103, in order to achieve start-end-point coupling of the effective test widths of the two adjacent scanning units 1.

[0022] In this embodiment, a total of N scanning units 1 are provided. To meet the requirements of areal density full inspection, the total inspection width of the scanning units 1 must correspond to N*w > width W of the test specimen. If the effective inspection widths w of the individual scanning units 1 remain different from each other, then w1+w2+...+wN > W.

[0023] Before a practical measurement check, each pixel detector of the line array detector 103 performs a standardization with reference to the pattern for areal density control, and then a full areal density check is carried out. Subsequently, the determined areal density control data are analyzed. The areal density data, determined by the individual scanning units 1 in two straight lines, are aligned along the winding direction. This yields an actual width of the test specimen depending on the magnification ratio.

[0024] For industry experts, it is undisputed that the present invention is not limited to the embodiments mentioned above, but rather encompasses the same or similar arrangements, which can be implemented differently, provided that there is no deviation from the nature or essential features of the present invention. The invention is not limited in its embodiments, but can be varied in many ways within the scope of the disclosure. In this context, all new individual and combination features disclosed in the description and / or drawings are considered essential to the invention. Any reference numeral in the claims is not to be treated as a limitation of the claim in question.

Claims

[1] Area density full control device comprising several scanning units (1) laid out along a winding direction of the test specimen, wherein all scanning units (1) are arranged in the same straight line along the width direction of the test specimen and every two scanning units (1) adjacent along the width direction of the test specimen are laid out in different straight lines, wherein the width of the test specimen is covered by the effective test widths of the scanning units (1). [2] Area density full control device according to claim 1, characterized by , that the effective test widths of the individual scanning units (1) are connected one after the other along the width direction of the test specimen, wherein the sum of the effective test widths of all scanning units (1) is greater than the width of the test specimen to be measured. [3] Area density full control device according to claim 1, characterized by, that all scanning units (1) are uniformly constructed and each scanning unit (1) comprises a beam source (101), a collimator (102) attached to the base of the beam source (101) and a line array detector (103) located vertically below the collimator (102), wherein the collimator (102) converts the beam emitted by the beam source (101) into a fan-shaped beam which shines onto the line array detector (103) and then produces a strip-shaped spot of light, covering the length of the line array detector (103), wherein the line array detector (103) receives the radiations from the beam source (101). [4] Area density full control device according to claim 3, characterized by, that several beam sources (101) and several collimators (102) are fixed in one housing, while several line array detectors (103) are all fixed in another housing, wherein a gap is provided between the two housings for receiving the through-body test specimen, wherein the plane of the test specimen remains parallel to the height planes of the beam sources (101) and the line array detectors (103). [5] Area density full control device according to claim 3, characterized by , that each beam source (101) interacts with a complementary line array detector (103) such that no beam source (101) throws its fan-shaped beam onto any other line array detector (103).

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