Surface treatment method of invar foil
By conducting internal stress testing and thinning treatment on the Invar foil, the problems of scratches, rust, and uneven stress in the Invar foil were solved, ensuring that the local flatness of the metal mask was qualified, thus improving production efficiency and product quality.
Patent Information
- Application Number
- CN202511578756.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-31
- Publication Date
- 2025-12-12
AI Technical Summary
Due to defects such as scratches and rust in the production process of the corrugated foil, the product is over-cut and the flatness of some areas is not up to standard. In addition, uneven stress causes the flatness of some areas to exceed the requirements, which affects the normal use of the metal mask.
By conducting internal stress tests on the Invar foil, the amount of thinning on the front and back sides is determined, and a half-etching thinning process is performed, etching to half the original thickness to measure the amount of warpage. The amount of thinning is allocated according to the amount of warpage to ensure that the local flatness meets the requirements.
It improves the surface condition of the corrugated foil, solves the local flatness problem caused by uneven stress, ensures the production quality of the metal mask, and avoids additional processing steps.
Smart Images
Figure CN121109943A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photomask manufacturing, and particularly to a surface treatment method for intaglio foil. Background Technology
[0002] Invar foil used in the production of Common Metal Masks (CMMs) suffers from surface defects such as scratches, rust, and dirt. These defects can lead to over-etching issues during the CMM production process, and the scratches and rust will ultimately be reflected in the finished product, affecting the normal use of the metal mask. Furthermore, the metal mask requires a local flatness of ≤50μm during manufacturing. However, commercially available Invar foil often exhibits uneven stress during production, resulting in local flatness exceeding the requirements after the foil is made into a metal mask, leading to product defects (NG). This necessitates additional processes to resolve the local flatness issue after the metal mask is made.
[0003] The above background information is provided to facilitate understanding of the present invention and is not intended to be publicly known technology disclosed to the general public prior to the application of this invention. Summary of the Invention
[0004] To address the aforementioned deficiencies, this invention provides a surface treatment method for insulated foil, which solves the problem of local flatness non-compliance caused by internal stress in insulated foil.
[0005] The technical solution is: a surface treatment method for inductor foil, comprising the following steps: S1, Test the internal stress of the invar foil; S2, based on the test results of S1, determine the front and back thinning amounts of the inductor foil; S4. Based on the front and back thinning amounts of S2, a mask is made from the invar foil, and the local flatness of the mask is detected.
[0006] Furthermore, in S1, the internal stress is tested by partially thinning the Invar foil to obtain the front and back warpage of the Invar foil after half-cutting. Partial thinning is etching the Invar foil to half its original thickness.
[0007] Further, in S2, determining the thinning amount includes the following steps: S21, determine whether the warping is greater on the front or back of the foil material; S22, Set the overall thinning depth required for the corrugated foil material to be thinned, denoted as S. 总 S 总 =Inverse foil thickness - target thickness; S23, Based on S21, determine which side receives a larger amount of thinning. The thinning amount on the front side is denoted as S. 正The amount of thinning on the reverse side is denoted as S. 反 S 总 =S 正 +S 反 .
[0008] Furthermore, in S23, S 正 =S 总 / 2-K*(warpage amount-50), where K is a constant, typically ranging from 0.3 to 0.5.
[0009] Furthermore, in S4, the local flatness is measured as follows: multiple detection points are set on the mask ribs, and the measurement endpoint of each detection point is 200μm away from the Cell boundary. The Cell is the opening of the mask sample, and the local flatness is obtained.
[0010] Furthermore, it also includes S3, which involves thinning the Invar foil based on the front and back thinning amounts of S2, and then testing the overall flatness of the thinned Invar foil.
[0011] Furthermore, in S3, the overall flatness of the test must be ≤5mm, and the edge waviness must be ≤3mm.
[0012] Furthermore, in S4, the local flatness of the mask needs to be ≤50μm.
[0013] Beneficial effects: The surface treatment technology of this invention improves the surface condition of Invar foil and solves the problem of uneven foil stress leading to poor local flatness of the product, thereby solving the defects in metal photomask production and finished products. The metal photomask produced can meet the flatness requirements without additional treatment. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the structure of the foil material after half-cutting in this invention; Figure 2 This is a schematic diagram illustrating the warping of the foil material after half-cutting in this invention. Figure 3 This is a schematic diagram of the metal mask sample structure of the present invention; Figure 4 This is a schematic diagram of the local flatness detection point structure of the present invention. Detailed Implementation
[0015] The invention will now be further described with reference to the accompanying drawings.
[0016] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection via an intermediate medium, or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0017] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In the description of this invention, "a plurality of" means two or more, unless otherwise precisely specified.
[0018] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0020] A surface treatment method for insulated foil includes the following steps: S1, Test the internal stress of the invar foil; S2, based on the test results of S1, determine the front and back thinning amounts of the inductor foil; S4. Based on the front and back thinning amounts of S2, a mask is made from the invar foil, and the local flatness of the mask is detected.
[0021] Furthermore, as a preferred embodiment, in S1, the internal stress is tested by partially thinning the Invar foil to obtain the front and back warpage of the Invar foil after half-cutting. Half-cutting thinning is etching the Invar foil to half of its original thickness.
[0022] Furthermore, preferably, in S2, determining the thinning amount includes the following steps: S21, determine whether the warping is greater on the front or back of the foil material; S22, Set the overall thinning depth required for the corrugated foil material to be thinned, denoted as S. 总 S 总 =Inverse foil thickness - target thickness; S23, Based on S21, determine which side receives a larger amount of thinning. The thinning amount on the front side is denoted as S. 正 The amount of thinning on the reverse side is denoted as S. 反 S 总 =S 正 +S 反 .
[0023] Furthermore, as a preferred option, in S23, S 正 =S 总 / 2-K*(warpage amount-50), where K is a constant, typically ranging from 0.3 to 0.5.
[0024] Furthermore, as a preferred embodiment, in S4, the local flatness is measured as follows: multiple detection points are set on the mask ribs, and the measurement endpoint of each detection point is 200μm away from the Cell boundary. The Cell is the opening of the mask sample, and the local flatness is obtained.
[0025] Furthermore, as a preferred embodiment, S3 is also included, in which the Invar foil is thinned according to the front thinning amount and the back thinning amount of S2, and the overall flatness of the Invar foil after thinning is detected.
[0026] Furthermore, as a preferred option, in S3, the overall flatness of the test should be ≤5mm and the edge waviness should be ≤3mm.
[0027] Furthermore, as a preferred embodiment, in S4, the local flatness of the mask needs to be ≤50μm.
[0028] Furthermore, as a preferred option, the thickness of the foil material is between 120 μm and 150 μm.
[0029] The following detailed description is provided through examples. In the detailed description, the thinning etching solution used is FeCl3 solution with the following parameters: specific gravity 1.5~1.58, no HCl, and temperature 48~52℃.
[0030] Example 1 A surface treatment method for insulated foil includes the following steps: S1. Internal stress testing was conducted on existing Inwa foil purchased from the market. A small sample (150mm x 30mm) was used for a half-crush test on both sides (the front and back sides of the Inwa foil were marked before testing). The warping of the Inwa foil after the half-crush test was observed. Figures 1-2 As shown, where Figure 1 This is a schematic diagram of the structure after the foil material has been partially carved. Figure 2 This is a schematic diagram of the warping of the ingot foil after half a mark, showing the amount of warping on the front and back of the ingot foil after half a mark.
[0031] Half-etching refers to etching away half the thickness of existing invar foil purchased from the market. For example, if the thickness of the invar foil is 120μm, then the thickness of the invar foil after S1 half-etching is 60μm.
[0032] The method for detecting warpage is not specifically limited here; either direct measurement or indirect measurement can be used, and those skilled in the art can choose according to their needs.
[0033] S2, Determine the amount of thinning. S21. Compare the warpage of the front and back sides of the inductor foil to determine whether the warpage is greater on the front or back. A larger warpage indicates greater internal stress on that side, denoted as F. 大面 A smaller warping indicates a smaller in-plane stress, denoted as F. 小面 .
[0034] S22, Set the overall thinning depth required for the foil material to be thinned (denoted as S). 总 ), S 总 = Due to the thickness of the foil material - target thickness.
[0035] S23, according to F 大面 and F 小面 Determine which side receives a larger amount of thinning; the thinning amount on the front side is denoted as S. 正 The amount of thinning on the reverse side is denoted as S. 反 S 总 =S 正 +S 反 .
[0036] If the front is F 大面 Then, less thinning is allocated to the front side, S 正 反 ,vice versa.
[0037] S3, take the same Invar foil material as S1 with the same dimensions as the mask to be produced (except for the length and width, everything else is the same, based on S2). 正 and S 反 The front and back sides of the Inwa foil are thinned, and the overall flatness and edge ripples of the thinned Inwa foil are tested.
[0038] If the overall flatness is ≤5mm and the edge waviness is ≤3mm, it indicates that the thinning amount determined by S2 meets the requirements.
[0039] S4, take the same Invar foil material as S1 with the same dimensions as the mask to be produced (except for the length and width, everything else is the same, based on S2). 正 and S 反 The foil material is thinned to make a mask.
[0040] The mask made Figures 3-4 As shown, Figure 3 This is a schematic diagram of the mask used in this invention (showing the detection points). Figure 4 This is a schematic diagram of the local flatness detection point structure of the present invention.
[0041] Detect the local flatness of the mask.
[0042] The method for measuring the local flatness of a mask is as follows: Detection points are set on the ribs of the mask. The measurement endpoint of each detection point is 200μm away from the cell boundary. The cell is the opening of the mask sample. Nine detection points can be set on one rib to obtain the Z-axis length of each detection point, thereby obtaining the local flatness of the mask.
[0043] If the local flatness of the mask is ≤50μm, it indicates that the thinning amount set in S2 meets the local flatness requirements.
[0044] When the overall flatness and edge waviness of S3 (Invar foil) meet the requirements, and the local flatness of S4 (mask) meets the requirements, the mask can be produced according to the thinning amount determined in S2.
[0045] In S23, S 正 =S 总 / 2-K*(warpage amount-50), where K is a constant, typically ranging from 0.3 to 0.5.
[0046] In the above-described method for processing insulated foil of the present invention, due to the fluidity of the chemical solution during the thinning process, it has stronger etching characteristics for protruding parts such as scratches. Therefore, the surface problems of the foil are solved during the thinning process.
[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A surface treatment method for insulated foil, characterized in that, Includes the following steps: S1, Test the internal stress of the invar foil; S2, based on the test results of S1, determine the front and back thinning amounts of the inductor foil; S4. Based on the front and back thinning amounts of S2, a mask is made from the invar foil, and the local flatness of the mask is detected.
2. The surface treatment method for Invar foil according to claim 1, characterized in that, In S1, the internal stress is tested by partially thinning the Invar foil to obtain the front and back warpage of the Invar foil after half-cutting. Half-cutting thinning is to etch the Invar foil to half of its original thickness.
3. The surface treatment method for Invar foil according to claim 2, characterized in that, In S2, determining the amount of thinning includes the following steps: S21, determine whether the warping is greater on the front or back of the foil material; S22, Set the overall thinning depth required for the corrugated foil material to be thinned, denoted as S. 总 S 总 =Inverse foil thickness - target thickness; S23, Based on S21, determine which side receives a larger amount of thinning. The thinning amount on the front side is denoted as S. 正 The amount of thinning on the reverse side is denoted as S. 反 S 总 =S 正 +S 反 .
4. The surface treatment method for Invar foil according to claim 3, characterized in that, In S23, S 正 =S 总 / 2-K*(warpage amount-50), where K is a constant, typically ranging from 0.3 to 0.
5.
5. The surface treatment method for Invar foil according to claim 3, characterized in that, In S4, the local flatness is measured as follows: multiple detection points are set on the mask ribs, and the measurement endpoint of each detection point is 200μm away from the Cell boundary. The Cell is the opening of the mask sample, and the local flatness is obtained.
6. The surface treatment method for Invar foil according to claim 3, characterized in that, It also includes S3, which involves thinning the Invar foil based on the front and back thinning amounts in S2, and then testing the overall flatness of the Invar foil after thinning.
7. The surface treatment method for Invar foil according to claim 6, characterized in that, In S3, the overall flatness of the test must be ≤5mm, and the edge wave must be ≤3mm.
8. The surface treatment method for Invar foil according to any one of claims 1-7, characterized in that, In S4, the local flatness of the mask needs to be ≤50μm.