Dry film photoetching inverted trapezoidal structure and preparation method thereof

Abstract

The invention discloses a dry film photoetching inverted trapezoidal structure and a preparation method thereof, and belongs to the technical field of microsystem packaging. The method comprises the steps of substrate cleaning, dry film pressing, exposure, developing, dry film pressing, exposure and developing. The method has the advantages that the problem that in the prior art, residual photoresist is removed after the metal layer is evaporated under the condition that a dry film exists on the substrate can be solved, and meanwhile the poor appearance such as metal layer scratching caused by wiping the residual photoresist is avoided. The method is simple in process, has no adverse effect on productivity, has adjustability, can adjust the height and width of the inverted trapezoid according to the evaporation angles of different evaporation devices, and has good application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of microsystem packaging, and in particular to a dry film photolithography inverted trapezoidal structure and a preparation method thereof. Background Art

[0002] At present, the production process of ceramic substrate packaging products is generally divided into steps such as cleaning, sputtering, coating, photolithography, and scribing, and the coating process is usually mainly divided into PVD (physical vapor deposition) and CVD (chemical vapor deposition). Among them, vacuum evaporation is a type of PVD process. It is a coating technology that evaporates materials through resistance or electron beam heating, vaporizes them, and condenses them on the substrate to form a film. It is widely used because of its advantages such as a wide range of materials to be plated, precise and controllable process, and continuous production.

[0003] In the vacuum evaporation process, it is often the case that a metal film with a specific pattern is obtained by evaporating a film on the surface of a substrate with a photolithography pattern. However, in the existing process, the photoresist is often concentrated around the metal after evaporation and cannot be completely removed. Usually, when encountering this process problem, most people remove it by wiping with acetone or tearing off the blue film, but this will introduce another new problem: scratches on the metal surface. Therefore, it is particularly important to solve the problem of desmearing residue after evaporation without introducing scratches on the metal surface. Summary of the invention

[0004] The technical problem to be solved by the present invention is how to solve the problem of adhesive residue after evaporating the metal layer in the presence of a dry film on the substrate in the prior art, and the problem of poor appearance such as scratches on the metal layer caused by wiping the adhesive residue.

[0005] The present invention solves the above technical problems through the following technical means:

[0006] A first aspect of the present invention provides a method for preparing an inverted trapezoidal structure by dry film lithography, comprising the following steps:

[0007] S1. Laminating the first layer of dry film: Place the cleaned substrate on the laminator, adjust the roller pressure to between 0.3 and 0.6 MPa, turn on the conveying button of the equipment, and place the first layer of dry film tightly on the surface of the substrate;

[0008] S2. Exposure of the first layer of dry film: Place the substrate with the first layer of dry film on the surface under an exposure machine for exposure. The exposure energy is determined according to the thickness of the dry film and is between 20 and 100 mj.

[0009] S3, development of the first layer of dry film: tear off the surface white film of the first layer of dry film after exposure, and put it into the automatic development line equipment for development;

[0010] S4, laminating the second layer of dry film: pressing the second layer of dry film tightly against the surface of the first layer of dry film by repeating the steps of S1, except that the roller pressure is adjusted to between 0.1 and 0.3 MPa; the width of the second layer of dry film is greater than that of the first layer of dry film;

[0011] S5, exposure of the second dry film: repeat the exposure step of S2;

[0012] S6, development of the second layer of dry film: repeat the development steps of S3 to obtain.

[0013] Preferably, in step S1, the material of the substrate may be but is not limited to any one of ALN, ALO, glass, SiC, HTCC, and LTCC.

[0014] Preferably, the size of the substrate may be, but is not limited to, any one of 2 inches, 3 inches, and 4.5 inches.

[0015] Preferably, the thickness of the first dry film layer and the second dry film layer is 10-45 μm (for example, 10 μm, 25 μm, 35 μm, 45 μm).

[0016] Preferably, in step S3, the developing speed is determined according to the dry film thickness, and the developing speed is between 0.6 and 0.9 m / min.

[0017] Preferably, the width of the first dry film layer is 100-300 μm.

[0018] Preferably, the width of the second dry film layer is 150-360 μm.

[0019] The second aspect of the present invention provides a dry film photolithography inverted trapezoidal structure obtained by the above-mentioned preparation method.

[0020] The beneficial effects of the present invention are:

[0021] 1. The present invention proposes a new inverted trapezoidal structure, which can fundamentally solve the problem of dry film residue after evaporation. In principle, the traditional dry film is usually a regular trapezoid or a regular quadrilateral after development. During coating, the evaporated material is not only deposited in the gaps between the dry films, but also a small amount is deposited on the side walls at the bottom of the dry film. The dry film at these locations has a strong adhesion to the metal layer, making it difficult to remove the dry film later (such as Figure 3 The inverted trapezoidal structure can prevent metal from being deposited on the side wall at the bottom of the dry film during evaporation, so that the dry film can be completely removed without any problems, and metal scratches caused by subsequent wiping can be avoided.

[0022] 2. The present invention can solve the deficiencies in the prior art and also avoid scratches caused by wiping and removing the glue residue. By exposing the dry film to different widths and stacking them to obtain an inverted trapezoidal structure, the problem of dry film residue existing in the existing dry film during evaporation is fundamentally solved. Compared with the existing process, the method of the present invention does not add any process flow, so it has no impact on the actual production efficiency, and has a good application prospect and application value in the field of microsystem packaging technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall structure of an inverted trapezoidal dry film in Example 1 of the present invention;

[0024] Figure 2 It is a schematic flow chart of each step of a method for preparing an inverted trapezoidal dry film in Example 1 of the present invention;

[0025] Figure 3 It is a schematic diagram of the principle of the existence of degumming residues in the evaporation process of the regular trapezoidal and regular quadrilateral structure dry film in the prior art;

[0026] Figure 4 It is a schematic diagram of the principle that there is no degumming residue after evaporating the metal layer of the dry film inverted trapezoidal structure in Example 1 of the present invention;

[0027] Figure 5 This is a comparison diagram of the dry film residue after the inverted trapezoidal dry film structure in Example 1 of the present invention and the regular quadrilateral dry film structure in the prior art are removed through the evaporation process;

[0028] Figure 6 A comparison diagram of the inverted trapezoidal dry film structure in Example 1 of the present invention and the dry film structure in Comparative Example 1;

[0029] Figure 7 A comparison diagram of the first dry film in Example 1 of the present invention and the first dry film in Comparative Example 2;

[0030] Figure 8 It is a comparison diagram of the inverted trapezoidal dry film structure in Example 1 of the present invention and the dry film structure in Comparative Example 3;

[0031] In the accompanying drawings, 1-substrate, 2-first dry film layer, 3-second dry film layer, 4-evaporated metal layer. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources.

[0034] If no specific techniques or conditions are specified in the examples, they can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0035] Embodiment 1:

[0036] like Figure 1 A dry film photolithography inverted trapezoidal process structure is shown, and the structure includes: a substrate, a first layer of dry film, and a second layer of dry film.

[0037] A method for preparing an inverted trapezoidal structure by dry film lithography,

[0038] like Figure 2 As shown, the method comprises the following steps:

[0039] S1. Lamination of the first layer of dry film: Place the cleaned substrate (the substrate is made of glass) on the laminator, select a dry film thickness of 45 μm, adjust the roller pressure to 0.3 MPa, turn on the conveying button of the equipment, and press the dry film tightly against the surface of the substrate;

[0040] S2, first layer dry film exposure: put the substrate with dry film on the surface under the exposure machine for exposure. The exposure energy is determined according to the thickness of the dry film. The exposure energy is 80mj and the width of the dry film is 300μm.

[0041] S3. Development of the first layer of dry film: tear off the surface white film of the dry film after exposure and put it into the automatic development line equipment. The development speed is determined according to the thickness of the dry film, and the development speed is 0.7m / min.

[0042] S4, second layer of dry film lamination: repeat the steps of S1, select the dry film thickness as 25μm, and adjust the roller pressure to 0.1MPa;

[0043] S5, exposure of the second dry film: repeat the steps of S2, the exposure energy is 40mj, and the width of the dry film is 360μm;

[0044] S6, developing the second layer of dry film: repeat the steps of S3, and the developing speed is 0.6 m / min;

[0045] from Figure 1 It can be seen that when two dry films with different widths (the second dry film is wider than the first) are superimposed together, an inverted trapezoidal structure can be formed.

[0046] from Figure 2 It can be seen that after two times of lamination, exposure and development on the substrate, a dry film with an inverted trapezoidal structure can be obtained.

[0047] The principle of the existence of degumming residue in the conventional dry film evaporation process of regular trapezoidal and regular quadrilateral structures is as follows: Figure 3 As shown in the figure, it can be seen that the dry film obtained by the prior art is usually a regular quadrilateral or regular trapezoidal structure. When the metal is evaporated and then the dry film is removed, the dry film usually remains and adheres to the metal side wall, making it difficult to remove completely.

[0048] The principle of the dry film inverted trapezoidal structure in Example 1 having no degumming residue after evaporating the metal layer is as follows Figure 4 As shown, from Figure 4 It can be seen that when the dry film is an inverted trapezoidal structure, the metal does not adhere to the dry film when evaporating the metal, so the dry film can be completely removed without any residue.

[0049] Comparison of the dry film residue after the inverted trapezoidal dry film structure in Example 1 and the regular quadrilateral dry film structure in the prior art are removed through the evaporation process. Figure 5 As shown, the inverted trapezoidal structure of Example 1 has no dry film residue, while the regular quadrilateral structure of the prior art has dry film residue.

[0050] Comparative Example 1:

[0051] The difference between this comparative example and Example 1 is that the exposure energy in step S2 is 150 mj, and the rest is the same as Example 1.

[0052] Conclusion: Exposure energy affects the width of the dry film. When the energy is greater than the value within the range, the shape of the double-layer dry film changes from an inverted trapezoid to a regular trapezoid, such as Figure 6 shown.

[0053] Comparative Example 2:

[0054] The difference between this comparative example and Example 1 is that the roller pressure in step S1 is adjusted to 0.1 MPa, and the rest is the same as Example 1.

[0055] Conclusion: The roller pressure during the lamination of the first layer of dry film affects the bonding force between the dry film and the substrate. When the pressure is less than the set value, the bonding force between the dry film and the substrate becomes poor. When the first layer of dry film is developed, the dry film will be directly separated from the substrate. Figure 7 shown.

[0056] Comparative Example 3:

[0057] The difference between this comparative example and Example 1 is that the roller pressure in step S4 is adjusted to 0.5 MPa, and the rest is the same as Example 1.

[0058] Conclusion: The roller pressure during lamination of the second layer of dry film affects the bonding force between the second layer of dry film and the first layer of dry film. When the pressure is higher than the set value, the second layer of dry film is directly crushed by the high pressure, and the protruding dry film at both ends is pressed on the first layer of dry film. Figure 8 shown.

[0059] Embodiment 2:

[0060] A method for preparing an inverted trapezoidal structure by dry film photolithography comprises the following steps:

[0061] S1. Lamination of the first layer of dry film: Place the cleaned substrate (the substrate is made of ALN) on the laminator, select a dry film thickness of 35μm, adjust the roller pressure to 0.4MPa, turn on the conveying button of the equipment, and press the dry film tightly against the surface of the substrate;

[0062] S2, first layer dry film exposure: put the substrate with dry film on the surface under the exposure machine for exposure. The exposure energy is determined according to the thickness of the dry film. The exposure energy is 20mj and the width of the dry film is 100μm.

[0063] S3. Development of the first layer of dry film: tear off the surface white film of the dry film after exposure and put it into the automatic development line equipment. The development speed is determined according to the thickness of the dry film, and the development speed is 0.6m / min.

[0064] S4, second layer of dry film lamination: repeat the steps of S1, select the dry film thickness as 10μm, and adjust the roller pressure to 0.2MPa;

[0065] S5, exposure of the second dry film: repeat the steps of S2, the exposure energy is 30mj, and the width of the dry film is 150μm;

[0066] S6. Development of the second dry film: repeat the steps of S3, with a development speed of 0.7 m / min.

[0067] Embodiment 3:

[0068] A method for preparing an inverted trapezoidal structure by dry film photolithography comprises the following steps:

[0069] S1. Lamination of the first layer of dry film: Place the cleaned substrate (the material of the substrate is ALO) on the laminator, select a dry film thickness of 45μm, adjust the roller pressure to 0.6MPa, turn on the conveying button of the equipment, and press the dry film tightly against the surface of the substrate;

[0070] S2, first layer dry film exposure: put the substrate with dry film on the surface under the exposure machine for exposure. The exposure energy is determined according to the thickness of the dry film. The exposure energy is 100mj and the width of the dry film is 150μm.

[0071] S3. Development of the first layer of dry film: tear off the white film on the surface of the dry film after exposure and put it into the automatic development line equipment. The development speed is determined according to the thickness of the dry film and the development speed is 0.8m / min.

[0072] S4, second layer of dry film lamination: repeat the steps of S1, select the dry film thickness as 35μm, and adjust the roller pressure to 0.2MPa;

[0073] S5, exposure of the second dry film: repeat the steps of S2, the exposure energy is 80mj, and the width of the dry film is 230μm;

[0074] S6. Development of the second dry film: repeat the steps of S3, with a development speed of 0.7 m / min.

[0075] The dry film photolithography inverted trapezoidal structures obtained in Example 2 and Example 3 also have no dry film residue after the dry film is removed through the evaporation process.

[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing an inverted trapezoidal structure by dry film lithography, characterized in that: The following steps are involved: S1. Laminating the first layer of dry film: Place the cleaned substrate on the laminator, adjust the roller pressure to between 0.3 and 0.6 MPa, turn on the conveying button of the equipment, and place the first layer of dry film tightly on the surface of the substrate; S2. Exposure of the first layer of dry film: Place the substrate with the first layer of dry film on the surface under an exposure machine for exposure. The exposure energy is determined according to the thickness of the dry film and is between 20 and 100 mj. S3, development of the first layer of dry film: tear off the surface white film of the first layer of dry film after exposure, and put it into the automatic development line equipment for development; S4, laminating the second layer of dry film: pressing the second layer of dry film tightly against the surface of the first layer of dry film by repeating the steps of S1, except that the roller pressure is adjusted to between 0.1 and 0.3 MPa; the width of the second layer of dry film is greater than that of the first layer of dry film; S5, exposure of the second dry film: repeat the exposure step of S2; S6, development of the second layer of dry film: repeat the development steps of S3 to obtain.

2. The preparation method according to claim 1, characterized in that: In step S1 , the material of the substrate is any one of ALN, ALO, glass, SiC, HTCC, and LTCC.

3. The preparation method according to claim 1, characterized in that: The size of the substrate is any one of 2 inches, 3 inches, and 4.5 inches.

4. The preparation method according to claim 1, characterized in that: The thickness of the first dry film layer and the second dry film layer is 10 to 45 μm.

5. The preparation method according to claim 1, characterized in that: In step S3, the developing speed is determined according to the dry film thickness, and the developing speed is between 0.6 and 0.9 m / min.

6. The preparation method according to claim 1, characterized in that: The width of the first dry film is 100-300 μm.

7. The preparation method according to claim 1, characterized in that: The width of the second dry film is 150-360 μm.

8. The preparation method according to claim 1, characterized in that: The width of the first dry film is 300 μm.

9. The preparation method according to claim 1, characterized in that: The width of the second dry film layer is 360 μm.

10. The dry film photolithography inverted trapezoidal structure obtained by the preparation method according to any one of claims 1 to 9.

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