Plasma equipment testing method

Abstract

The invention relates to a plasma equipment testing method, which comprises the following steps of: drilling testing holes with different apertures on a testing plate which can be repeatedly used, dividing the testing plate into a first sub-plate and a second sub-plate along the testing holes, and arranging semicircular holes on the cutting surfaces of the first sub-plate and the second sub-plate, after the hole wall of the semicircular hole is coated with a machine coating, the first sub-plate and the second sub-plate are combined into a complete test plate, then the test plate is put into plasma equipment to be etched, and the test plate is separated after etching; directly measuring the allowance of the organic coating on the hole wall of the first sub-plate and / or the second sub-plate by using a metallographic microscope, a hundred-time lens, a ten-time lens and other measuring tools so as to analyze the etching capability of the plasma equipment; according to the method, the test plate can be reused, the test cost is low, the etching capability of the plasma equipment can be visually analyzed through a measuring tool, slicing analysis does not need to be carried out on each hole, and the test efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of plasma equipment, and in particular to a method for testing a plasma equipment. Background Art

[0002] Plasma is the fourth state of matter, consisting of ionized gas, including free electrons, ions, and neutral particles. A Plasma machine (plasma equipment) is an industrial equipment that uses plasma technology for surface treatment, cleaning, etching, or material modification. It is widely used in the semiconductor industry and the circuit board industry. For example, in the production of circuit boards, colloids will remain in the holes after drilling, and these residual colloids will affect the subsequent processes. Therefore, it is necessary to perform plasma degumming on the circuit board in the Plasma machine to etch away the residual colloids in the holes. The larger the aspect ratio (board thickness to hole diameter), the more difficult it is to remove the residual colloids in the holes. A very important performance of the Plasma machine is the deep etching ability, that is, the maximum aspect ratio at which the residual colloids in the holes can be completely etched away. Usually, before a Plasma machine leaves the factory to detect its deep etching ability, or before use to detect its etching ability, a circuit board that has undergone normal lamination and drilling processes is used as a sample circuit board. The circuit board is placed in the corresponding Plasma machine for plasma degumming. After plasma degumming, each hole is sliced and analyzed, and finally the etching ability of the Plasma machine is obtained; the circuit boards used in this testing method are disposable and need to be discarded after use and cannot be reused. Each tested circuit board is manufactured through the processes of lamination and drilling, which takes a long time, has a high testing cost, and each hole needs to be sliced and analyzed, which is time-consuming and laborious, and the testing efficiency is very low. Summary of the Invention

[0003] In order to overcome the above problems, the present invention provides a method for testing a plasma equipment. The technical solution adopted by the present invention to solve its technical problems is as follows: A method for testing a plasma equipment includes the following steps: Step S1: Provide a test board resistant to plasma etching, and drill a number of test holes with different diameters through the upper and lower surfaces on the test board; Step S2: Vertically divide the test board along the test holes into a first sub-board and a second sub-board. The cutting surfaces of the first sub-board and the second sub-board both include semi-circular holes; Step S3: Coat an organic coating on the hole walls of the semi-circular holes of the first sub-board and the second sub-board; Step S4: Detachably fix and join together the first sub-board and the second sub-board with the hole walls coated with the organic coating to form a test board, and the semi-circular holes are correspondingly combined into test holes; Step S5: Place the combined test board in the plasma equipment for etching, and take out the test board after the etching is completed; Step S6: Split the test board into a first sub-board and a second sub-board, and measure the remaining amount of the organic coating in the semi-circular holes of the first sub-board and / or the second sub-board by a measuring tool to analyze the etching ability of the plasma equipment.

[0004] Further, the test board is made of stainless steel / ceramics / quartz / glass.

[0005] Further, the thickness of the test board is 2 mm - 12 mm, and the aperture of the test hole is 0.15 mm - 5 mm.

[0006] Further, in Step S2, the cutting surfaces of the first sub-board and the second sub-board and the hole walls of the semi-circular holes are finely polished. The roughness RA of the cutting surfaces of the first sub-board and the second sub-board is ≤ 0.8, and the roughness RA of the hole walls of the semi-circular holes is ≤ 0.8.

[0007] Further, the dyne value of the organic coating on the hole walls of the semi-circular holes is greater than or equal to 20 and less than or equal to 45.

[0008] Further, in Step S4, alignment posts and fixing holes are vertically arranged on the cutting surface of the second sub-board, and alignment holes and bolt holes penetrating the first sub-board are vertically arranged on the cutting surface of the first sub-board; the first sub-board is sleeved on the alignment posts through the alignment holes to be aligned and combined with the second sub-board, and fastening bolts are inserted into the bolt holes and fastened into the fixing holes to detachably fixedly connect the first sub-board and the second sub-board.

[0009] Further, in Step S6, the distance from the topmost end of the remaining organic coating in the semi-circular hole to the top orifice of the semi-circular hole is measured by a measuring tool and denoted as a, the distance from the lowermost end of the remaining organic coating in the semi-circular hole to the bottom orifice of the semi-circular hole is measured by a measuring tool and denoted as b, the thickness of the test board is denoted as H, the diameter of the test hole is denoted as d, the thickness-diameter ratio of the test hole is H / d, and the deep etching ability of the plasma equipment corresponding to the thickness-diameter ratio is (a + b) / H.

[0010] Further, in Step S6, a test hole with the minimum aperture d1 where (a + b) / H = 1 is found by a measuring tool, a circuit board with a thickness of H is provided, a hole with an aperture of d1 is drilled on the circuit board, the circuit board is put into the plasma equipment for etching and then taken out, and the hole with an aperture of d1 on the circuit board is sliced and analyzed.

[0011] Further, holes with diameters of d1 - 0.1 mm, d1 - 0.05 mm, d1 + 0.05 mm, and d1 + 0.1 mm are drilled on the circuit board at the same time, and these holes are sliced and analyzed after plasma etching.

[0012] Further, in step S6, the distance from the topmost point of the remaining organic coating in the semi-circular hole to the top orifice of the semi-circular hole is measured by a measuring tool and denoted as a, the distance from the lowermost point of the remaining organic coating in the semi-circular hole to the bottom orifice of the semi-circular hole is measured by a measuring tool and denoted as b, the thickness of the test plate is denoted as H, and the etching uniformity of the plasma equipment is H / (a - b)².

[0013] The beneficial effects of the present invention are as follows: This test method uses a reusable test plate. Test holes with different diameters are drilled on the test plate, and the test plate is divided into a first sub-plate and a second sub-plate along the test holes. The cutting surfaces of the first sub-plate and the second sub-plate both include semi-circular holes. After applying an organic coating on the hole walls of the semi-circular holes, the first sub-plate and the second sub-plate are combined into a complete test plate. Then, the test plate is placed in a plasma equipment for etching. After etching, the test plate is separated, and measuring tools such as a metallurgical microscope, a hundred-power microscope, and a ten-power microscope are used to directly measure the remaining amount of the organic coating on the hole walls of the first sub-plate and / or the second sub-plate, so as to analyze the etching ability of the plasma equipment; the test plate in this method can be reused, the test cost is low, and this method can directly analyze the etching ability of the plasma equipment through measuring tools without the need to perform slice analysis on each hole, improving the test efficiency. Description of the Drawings

[0014] The present invention will be further described below in conjunction with the drawings and specific embodiments, where: Figure 1 is a three-dimensional view and a partial enlarged view of the test plate; Figure 2 is an exploded view of the test plate; Figure 3 is a three-dimensional view of the first sub-plate; Figure 4 is a three-dimensional view of the second sub-plate; Figure 5 is a schematic diagram of measuring the remaining amount of the organic coating in the semi-circular hole.

[0015] Reference Signs of the Drawing Numbers: 100, test plate; 101, test hole; 102, first sub-plate; 103, second sub-plate; 104, cutting surface; 105, semi-circular hole; 106, alignment post; 107, fixing hole; 108, alignment hole; 109, bolt hole; 110, fastening bolt. Detailed Embodiments

[0016] In order to better understand the purpose, structure, and function of the present invention, the specific embodiments of the "test method for a plasma equipment" of the present invention will be further described in detail below in conjunction with the drawings.

[0017] The test method of this embodiment includes the following steps: Step S1: Refer to Figure 1 , provide a test board 100 resistant to plasma etching, and drill a number of test holes 101 with different diameters through the upper and lower surfaces of the test board 100. Preferably, the test holes 101 are distributed in a straight line; Step S2: Refer to Figures 2 - 4 , vertically divide the test board 100 along the test holes 101 into a first sub-board 102 and a second sub-board 103. The cutting surfaces 104 of the first sub-board 102 and the second sub-board 103 both include semi-circular holes 105; Step S3: Coat the inner walls of the semi-circular holes 105 of the first sub-board 102 and the second sub-board 103 with an organic coating; Step S4: Detachably fix and join together the first sub-board 102 and the second sub-board 103 coated with the organic coating along the cutting surface 104 to form the test board 100. The semi-circular holes 105 of the first sub-board 102 and the second sub-board 103 are correspondingly combined into the test holes 101; Step S5: Place the combined test board 100 in a plasma device for etching. After the etching is completed, take out the test board 100; Step S6: Disassemble the test board 100 into the first sub-board 102 and the second sub-board 103, and directly measure the remaining amount of the organic coating in the semi-circular holes 105 of the first sub-board 102 and / or the second sub-board 103 through measuring tools such as a metallurgical microscope, a hundred-power microscope, and a ten-power microscope, so as to intuitively analyze the etching ability of the plasma device based on the measurement data of the remaining amount of the organic coating.

[0018] Using this test method, the test board 100 can be reused, greatly saving the test cost. Moreover, this method can directly measure the remaining amount of the organic coating through measuring tools such as a metallurgical microscope, a hundred-power microscope, and a ten-power microscope to analyze the etching ability of the plasma device, without the need to slice and analyze each hole on the circuit board as before, improving the measurement efficiency.

[0019] Furthermore, in this embodiment, the test board 100 is preferably made of stainless steel / ceramics / quartz / glass materials, which are corrosion-resistant and low-cost, and are conducive to repeated use.

[0020] More specifically, in this embodiment, the thickness of the test board 100 is 2 mm - 12 mm, preferably 8 mm; the aperture of the test hole 101 is 0.15 mm - 5 mm. A number of test holes 101 with different diameters are arranged on the test board 100, and the hole diameters form an arithmetic progression with a common difference of 0.05 mm to simulate all possible aperture diameters on the circuit board.

[0021] Further, in step S2, the cutting surfaces 104 of the first sub-board 102 and the second sub-board 103 and the hole walls of the semi-circular holes 105 are finely polished so that the roughness RA of the cutting surface 104 of the first sub-board 102 and the second sub-board 103 is ≤ 0.8, and the roughness RA of the hole walls of the semi-circular holes 105 is ≤ 0.8. This ensures that when the first sub-board 102 and the second sub-board 103 are combined, their cutting surfaces fit seamlessly, and the semi-circular holes 105 can be seamlessly combined into a complete test hole 101, preventing the organic coating on the hole walls from penetrating into the gaps and affecting the test accuracy. Moreover, the dyne value of the organic coating on the hole walls of the semi-circular holes 105 is greater than or equal to 20 and less than or equal to 45 to simulate the adhesion of the residual glue on the hole walls of the circuit board.

[0022] Further refer to Figures 2 - 4 , in step S4, alignment posts 106 and fixing holes 107 are vertically provided on the cutting surface 104 of the second sub-board 103, and alignment holes 108 and bolt holes 109 penetrating the first sub-board 102 are vertically provided on the cutting surface 104 of the first sub-board 102. The first sub-board 102 is sleeved on the alignment posts 106 through the alignment holes 108 and slides along the alignment posts 106 to quickly align and combine with the second sub-board 103. The fastening bolts 110 are inserted into the bolt holes 109 and fastened into the fixing holes 107 to detachably fix and connect the first sub-board 102 to the second sub-board 103, facilitating the disassembly and combination of the first sub-board 102 and the second sub-board 103.

[0023] Further refer to Figure 5 , in step S6, the distance from the top of the remaining organic coating in the semi-circular hole 105 to the top orifice of the semi-circular hole 105 is measured by a measuring tool and denoted as a, and the distance from the bottom of the remaining organic coating in the semi-circular hole 105 to the bottom orifice of the semi-circular hole 105 is measured by a measuring tool and denoted as b. The thickness of the test board 100 is denoted as H, and the diameter of the test hole 101 is denoted as d. Then the thickness-diameter ratio of the test hole 101 is H / d, and the deep etching ability of the plasma device at this thickness-diameter ratio is (a + b) / H. A value of (a + b) / H equal to 1 indicates that the plasma device can completely etch the residual glue in the hole with a thickness of H and a diameter of d. A value of (a + b) / H less than 1 indicates that the plasma device cannot completely etch the residual glue in the hole with a thickness of H and a diameter of d, and the smaller the value of (a + b) / H, the worse the deep etching ability of the plasma device. As long as the hole d1 with (a + b) / H equal to 1 and the smallest aperture is found, the maximum thickness-diameter ratio H / d1 that the plasma device can etch can be obtained.

[0024] More specifically, in some embodiments, for a circuit board made of special materials, in order to improve the accuracy of detection, a test hole 101 with the smallest aperture d1 where (a + b) / H = 1 is found by measurement using a measuring tool. Meanwhile, a circuit board with a thickness of H made of special materials through lamination is provided, and a hole with an aperture of d1 is drilled on the circuit board. The circuit board is taken out after being etched in a plasma device, and the hole with an aperture of d1 on the circuit board is sliced and analyzed to obtain the deep etching ability of the plasma device for the hole with an aperture of d1 on the circuit board made of this special material. Although the hole still needs to be sliced and analyzed here, the corresponding sliced aperture d1 has been screened out through the test method of the present invention, greatly reducing the number of holes that need to be sliced, that is, reducing the influence of material differences on the test accuracy, and at the same time improving the test efficiency. Further, in order to make the test more accurate and prevent the influence caused by errors, holes with diameters of d1 - 0.1 mm, d1 - 0.05 mm, d1 + 0.05 mm, and d1 + 0.1 mm are drilled on the circuit board at the same time, and these holes are all sliced and analyzed after plasma etching.

[0025] More specifically, referring to Figure 5 , in step S6, the distance from the topmost point of the remaining organic coating in the semi-circular hole 105 to the top orifice of the semi-circular hole 105 is measured by a measuring tool and denoted as a, and the distance from the lowermost point of the remaining organic coating in the semi-circular hole 105 to the bottom orifice of the semi-circular hole 105 is measured by a measuring tool and denoted as b. The thickness of the test board 100 is denoted as H, and the etching uniformity of the plasma device is characterized by H / (a - b)²; the smaller the value of H / (a - b)², the greater the difference in the etching degree of the plasma device on both sides of the test board 100, and the worse the etching uniformity of the plasma device; the larger the value of H / (a - b)², the smaller the difference in the etching degree of the plasma device on both sides of the test board 100, and the better the etching uniformity of the plasma device. In theory, when a = b, the above formula is invalid, and the etching uniformity of the plasma is the best. It should be noted that if the method of slicing and analyzing after drilling and etching the previous circuit board is used, usually 6 points are evenly taken on the hole wall after slicing, and the recessed depth of the PP layer (Prepreg, semi-cured sheet) etched on the hole wall at these 6 points is measured by a metallurgical microscope. Then, the range of the 6 depth values is divided by the average value to characterize the etching uniformity. This method is not only complex in slicing and analyzing, but also the recessed depth of the PP layer etched is small (in the micron level), which is difficult to measure, and the data accuracy is greatly affected by various factors such as the instrument accuracy. The organic coating in this method is evenly coated on the hole wall, the data a and b are simple to measure, and the values of a and b are relatively large (in the millimeter level), and the data error is little affected by the equipment accuracy. Using this method to test the etching uniformity ability of the plasma device is simple, convenient, and highly accurate.

[0026] It is understood that the present invention is described by way of some embodiments. Those skilled in the art will appreciate that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present invention. Additionally, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present invention.

[0027] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In the description of this application, "a plurality of" is understood as "at least two". "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The connection between A and B can represent: A is directly connected to B and A is connected to B through C. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

Claims

1. A plasma equipment testing method, characterized in that: The steps include: Step S1: providing a plasma etching resistant test board (100), and drilling a plurality of test holes (101) with different diameters penetrating the upper and lower surfaces of the test board (100); Step S2: vertically dividing the test plate (100) along the test hole (101) into a first sub-plate (102) and a second sub-plate (103), wherein the cutting surfaces (104) of the first sub-plate (102) and the second sub-plate (103) both include semicircular holes (105); Step S3: coating the hole walls of the semicircular holes (105) of the first sub-plate (102) and the second sub-plate (103) with an organic coating; Step S4: the first sub-plate (102) and the second sub-plate (103) with the hole walls coated with organic coating are detachably fixedly spliced ​​together to form the test plate (100), and the semicircular holes (105) are correspondingly combined to form the test holes (101); Step S5: placing the assembled test board (100) in a plasma device for etching, and taking out the test board (100) after the etching is completed; Step S6: splitting the test board (100) into the first sub-board (102) and the second sub-board (103), and measuring the residual amount of organic coating in the semicircular hole (105) of the first sub-board (102) and / or the second sub-board (103) by a measuring tool to analyze the etching capability of the plasma device.

2. A plasma equipment testing method according to claim 1, characterized in that: The test plate (100) is made of stainless steel / ceramic / quartz / glass.

3. A plasma equipment testing method according to claim 2, characterized in that: The test plate (100) has a thickness of 2 mm to 12 mm, and the test hole (101) has a diameter of 0.15 mm to 5 mm.

4. A plasma equipment testing method according to claim 1, characterized in that: In step S2, the cutting surfaces (104) of the first sub-plate (102) and the second sub-plate (103) and the hole walls of the semicircular holes (105) are finely polished, wherein the roughness of the cutting surfaces (104) of the first sub-plate (102) and the second sub-plate (103) is RA≤0.8, and the roughness of the hole walls of the semicircular holes (105) is RA≤0.

8.

5. A plasma equipment testing method according to claim 4, characterized in that: The dyne value of the organic coating on the hole wall of the semicircular hole (105) is greater than or equal to 20 and less than or equal to 45.

6. A plasma equipment testing method according to claim 5, characterized in that: In step S4, an alignment column (106) and a fixing hole (107) are vertically arranged on the cutting surface (104) of the second sub-plate (103), and an alignment hole (108) and a bolt hole (109) penetrating the first sub-plate (102) are vertically arranged on the cutting surface (104) of the first sub-plate (102); the first sub-plate (102) is sleeved on the alignment column (106) through the alignment hole (108) to be aligned with the second sub-plate (103), and a fastening bolt (110) is passed through the bolt hole (109) and fastened into the fixing hole (107) to detachably fix the first sub-plate (102) and the second sub-plate (103).

7. A plasma equipment testing method according to any one of claims 1 to 6, characterized in that: In step S6, the distance from the top of the remaining organic coating in the semicircular hole (105) to the top opening of the semicircular hole (105) is measured by the measuring tool as a, and the distance from the bottom of the remaining organic coating in the semicircular hole (105) to the bottom opening of the semicircular hole (105) is measured by the measuring tool as b. The thickness of the test plate (100) is recorded as H, the diameter of the test hole (101) is recorded as d, the aspect ratio of the test hole (101) is H / d, and the deep etching capability of the plasma equipment under the corresponding aspect ratio is (a+b) / H.

8. A plasma equipment testing method according to claim 7, characterized in that: In step S6, the test hole (101) with the minimum aperture d1 where (a+b) / H=1 is measured by the measuring tool, a circuit board with a thickness of H is provided, a hole with an aperture d1 is drilled on the circuit board, the circuit board is placed in a plasma device for etching and then taken out, and the hole with an aperture d1 on the circuit board is sliced ​​and analyzed.

9. A plasma equipment testing method according to claim 8, characterized in that: Holes with diameters of d1-0.1mm, d1-0.05mm, d1+0.05mm, and d1+0.1mm are drilled on the circuit board at the same time, and these holes are sliced ​​and analyzed after plasma etching.

10. A plasma equipment testing method according to any one of claims 1 to 6, characterized in that: In step S6, the distance from the top of the remaining organic coating in the semicircular hole (105) to the top opening of the semicircular hole (105) is measured by the measuring tool as a, and the distance from the bottom of the remaining organic coating in the semicircular hole (105) to the bottom opening of the semicircular hole (105) is measured by the measuring tool as b. The thickness of the test plate (100) is recorded as H, and the etching uniformity of the plasma equipment is H / (ab)².

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