Method for improving adhesion of chalcogenide glass coating

Abstract

A method for improving the adhesion of a chalcogenide glass coating includes the steps of: step one, placing a chalcogenide glass lens to be coated in a cleaning solution for soaking; step two, wiping the surface of the soaked chalcogenide glass lens clean with a piece of absorbent cotton; step three, placing the wiped chalcogenide glass lens in a mixed solution of acetone and alcohol for storage; step four, removing the chalcogenide glass lens from the mixed solution and performing ultrasonic cleaning during the preparation time before coating; step five, removing the ultrasonically cleaned chalcogenide glass lens and performing IPA drying; and step six, removing the IPA-dried chalcogenide glass lens and performing coating. Thus, the adhesion between the coating and the chalcogenide glass lens after coating of the chalcogenide glass is improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of vacuum coating, and more particularly to a method for improving the adhesion of chalcogenide glass coating. BACKGROUND

[0002] The coefficient of expansion of infrared chalcogenide glass material is high and the intrinsic stress is large, so the firmness between the chalcogenide glass substrate and the film layer and each film layer, the coefficient of thermal expansion is not matched, and the phenomenon of excessive interface stress exists, so the chalcogenide glass lens is prone to cause film peeling or film cracking after coating. SUMMARY

[0003] In view of the problems in the background art, the purpose of the present disclosure is to provide a method for improving the adhesion of chalcogenide glass coating, which can improve the adhesion between the film layer and the chalcogenide glass lens after chalcogenide glass coating.

[0004] Thus, a method for improving the adhesion of chalcogenide glass coating includes the following steps: step one, placing the chalcogenide glass lens to be coated into a cleaning solution for soaking; step two, wiping the surface of the soaked chalcogenide glass lens with degreasing cotton; step three, placing the wiped chalcogenide glass lens in a mixed solution of acetone and alcohol for storage; step four, removing the chalcogenide glass lens from the mixed solution and then ultrasonic cleaning during the preparation time before coating; step five, taking out the ultrasonic cleaned chalcogenide glass lens and performing IPA drying; step six, taking out the IPA dried chalcogenide glass lens for coating.

[0005] The beneficial effects of the present disclosure are as follows.

[0006] In the method for improving the adhesion of the chalcogenide glass coating in the present disclosure, the oil stains adhered to the surface of the chalcogenide glass lens can be removed by soaking in the cleaning solution and wiping with the absorbent cotton; the oxidation of the chalcogenide glass lens wiped clean can be avoided by storing the chalcogenide glass lens wiped clean in the mixed solution of acetone and alcohol; for the chalcogenide glass lens stored in the mixed solution of acetone and alcohol, the chalcogenide glass lens is taken out from the mixed solution only before coating (i.e. within the preparation time before coating), and then the subsequent ultrasonic cleaning and IPA drying are performed, (i.e. the time point when the chalcogenide glass lens is taken out from the mixed solution is taken as the preparation time before coating), so that the chalcogenide glass lens taken out from the mixed solution but still subjected to the subsequent ultrasonic cleaning and IPA drying can be avoided from being left for too long before coating, and if the remaining time is too long (i.e. the time interval from the time point when the chalcogenide glass lens is taken out from the mixed solution to the formal start of coating exceeds the preparation time before coating), the chalcogenide glass lens needs to be subjected to additional storage steps and means to prevent surface oxidation, and if such additional storage steps and means are not adopted, the surface of the chalcogenide glass coating will be oxidized; the surface micro-pollutants are further removed by ultrasonic cleaning, and the cleaning reagent of the chalcogenide glass lens subjected to ultrasonic cleaning is removed by IPA vapor during IPA drying. Through the surface treatment process of steps one to five, the surface cleanliness of the chalcogenide glass lens before coating is improved, which is conducive to improving the adhesion between the coating and the chalcogenide glass lens after coating. DETAILED DESCRIPTION

[0007] It will be understood that the disclosed embodiments are merely examples of the present disclosure, which can be implemented in various forms, and therefore, the specific details disclosed herein should not be interpreted as limiting, but merely as a basis for teaching a person of ordinary skill in the art to implement the present disclosure in various ways.

[0008] [Method for improving the adhesion of the chalcogenide glass coating]

[0009] The method for improving the adhesion of the chalcogenide glass coating in the present disclosure comprises the following steps:

[0010] Step one, soaking the chalcogenide glass lens to be coated in a cleaning solution;

[0011] Step two, wiping the surface of the chalcogenide glass lens soaked with absorbent cotton to clean the chalcogenide glass lens;

[0012] Step three, storing the chalcogenide glass lens wiped clean in a mixed solution of acetone and alcohol;

[0013] Step four, taking out the chalcogenide glass lens from the mixed solution during the preparation time before coating and then performing ultrasonic cleaning;

[0014] Step five, taking out the chalcogenide glass lens cleaned by ultrasonic cleaning and performing IPA drying;

[0015] Step six, taking out the chalcogenide glass lens dried by IPA and performing coating.

[0016] In the method for improving the adhesion of chalcogenide glass coating in the present disclosure, the oil stains adhered to the surface of the chalcogenide glass lens can be removed by immersion in the cleaning solution and wiping with the surface of the degreasing cotton; the oxidation of the chalcogenide glass lens cleaned and wiped can be avoided by storing the chalcogenide glass lens cleaned and wiped in the mixed solution of acetone and alcohol; for the chalcogenide glass lens stored in the mixed solution of acetone and alcohol, the chalcogenide glass lens is taken out from the mixed solution only before coating (i.e. during the preparation time before coating), and then subsequent ultrasonic cleaning and IPA drying are performed (i.e. the time point of taking out the chalcogenide glass lens from the mixed solution is taken as the preparation time before coating), so that the chalcogenide glass lens taken out from the mixed solution too early but still needs to wait for a long time after the subsequent ultrasonic cleaning and IPA drying are completed can be avoided; if the time interval from the time point of taking out the chalcogenide glass lens from the mixed solution to the time point of starting coating exceeds the preparation time before coating, the chalcogenide glass lens needs to be stored by another storage step and means to prevent surface oxidation, and if the other storage step and means are not used, the surface of the chalcogenide glass coating will be oxidized; the surface micro-pollutants are further removed by ultrasonic cleaning, and the cleaning reagent of the chalcogenide glass lens cleaned by ultrasonic cleaning is removed by IPA vapor during IPA drying. The surface cleanliness of the chalcogenide glass lens before coating is improved by the surface treatment process of steps one to five, which is conducive to improving the adhesion between the coating and the chalcogenide glass lens after coating.

[0017] In step one, the chalcogenide glass lens to be coated can be a polished or single-pointed chalcogenide glass lens.

[0018] In step one, the cleaning solution can be a mixed solution of dishwashing detergent and pure water, the volume ratio of dishwashing detergent to pure water is (1-2):30, the temperature of the cleaning solution is 25-35℃, and the immersion time is 20-30 min.

[0019] In step one, the dishwashing detergent can be selected from kitchen dishwashing detergents, such as Jove high-efficiency dishwashing detergent, Liby dishwashing detergent, and Chuanhua dishwashing detergent.

[0020] In step two, the wiping method using the absorbent cotton is wiping in the cleaning solution in which the chalcogenide glass lens is soaked, and the force used is less than 5N, i.e. the absorbent cotton is lightly wiped by hand, so as to avoid scratches on the surface of the chalcogenide glass lens.

[0021] In step three, the mixed solution of acetone and alcohol is prepared by volume ratio of 1:1 of acetone and alcohol, and the purity of acetone and alcohol is greater than 99%. The mixed solution prepared by volume ratio of 1:1 of acetone and alcohol has the characteristics of low volatility for long-term maintenance, which is not only beneficial to the stability of preservation, but also beneficial to reduce the cost caused by the volatility of the mixed solution.

[0022] In step four, the sequence of ultrasonic cleaning is first alkaline detergent ultrasonic cleaning and then pure water ultrasonic cleaning. The first alkaline detergent ultrasonic cleaning can quickly remove the micro-pollutants on the surface of the chalcogenide glass lens, and then the pure water ultrasonic cleaning is beneficial to remove the residues of the alkaline detergent ultrasonic cleaning. For example, the alkaline detergent can be AK191.

[0023] In step four, the frequency of ultrasonic cleaning is 40-60HZ, the time of ultrasonic cleaning is 2-5min, and the temperature of ultrasonic cleaning is 35-45℃. The temperature of ultrasonic cleaning is slightly higher than the temperature of the soaking cleaning solution in step one, so that the combination of slightly higher temperature cleaning reagent and ultrasonic wave will be beneficial to improve the thoroughness and efficiency of removing the micro-pollutants on the surface of the chalcogenide glass lens.

[0024] In step four, the preparation time before coating can be within 2 hours.

[0025] In step five, the heating temperature of IPA drying is 75-85℃, and the drying time is 2-4min.

[0026] In steps one to five, the chalcogenide glass lens is carried on the same fixture, so that when the chalcogenide glass lens is placed or taken out in steps one, three to five, only the placing and taking fixture is needed, avoiding secondary pollution caused by human hand touching the chalcogenide glass lens. In addition, using the same fixture is also beneficial to improve the production efficiency.

[0027] In step six, the coating can be vacuum evaporation coating or vacuum sputtering coating. Similarly, in order to improve the coating efficiency, the coating in step six will be carried out in another fixture, i.e. the fixture carrying the IPA dried chalcogenide glass lens is taken out, the chalcogenide glass lens is taken out from the fixture by a mechanical hand and placed into another fixture, and finally the another fixture is placed into the coating equipment for coating. In addition, the material of the coating is selected according to specific needs, for example, germanium (Ge), zinc sulfide (ZnS), ytterbium fluoride (YbF3), zinc selenide (ZnSe) and the like.

[0028] [TEST]

[0029] Example 1

[0030] The sulfide glass coating process adopts the following steps:

[0031] Step one, a clamp carrying the sulfide glass lens to be coated is placed in a cleaning solution for soaking, the sulfide glass lens to be coated is a polished sulfide glass lens with a diameter of 93 mm and a thickness of 4 mm, the cleaning solution is a mixture of detergent and pure water, the volume ratio of detergent to pure water is 1:30, the temperature of the cleaning solution is 30℃, the soaking time is 25 min, and the detergent is Jove high-efficiency detergent;

[0032] Step two, the soaked sulfide glass lens is wiped clean with degreasing cotton on the surface of the sulfide glass lens, the wiping method of the degreasing cotton is vertical downward wiping in the cleaning solution for soaking the sulfide glass lens, the force used is light wiping, and each part of the surface of the sulfide glass lens to be coated is wiped;

[0033] Step three, the wiped sulfide glass lens is transferred by the clamp and placed in a mixed solution of acetone and alcohol for preservation, the mixed solution is prepared by 1:1 volume ratio of acetone and alcohol, and the purity of acetone and alcohol is greater than 99%;

[0034] Step four, during the preparation time before coating, the clamp together with the sulfide glass lens is taken out from the mixed solution and then ultrasonic cleaned together with the sulfide glass lens, the preparation time before coating is 2 hours, the sequence of ultrasonic cleaning is first alkaline detergent ultrasonic cleaning and then pure water ultrasonic cleaning, the frequency of ultrasonic cleaning is 50HZ, the time of ultrasonic cleaning is 2 min, the temperature of ultrasonic cleaning is 35℃, and the alkaline detergent is AK191;

[0035] Step five, the ultrasonic cleaned sulfide glass lens is taken out and dried by IPA through the clamp together with the sulfide glass lens, the heating temperature of IPA drying is 80℃, and the drying time is 3 min;

[0036] Step six, the IPA dried sulfide glass lens is taken out through the clamp, then the sulfide glass lens is taken out from the clamp by a mechanical hand and placed into another clamp, finally the other clamp is placed into a coating device for coating, the material of the film layer is germanium, the coating adopts electron beam evaporation vacuum coating, and the thickness of the germanium film layer is 30 nm.

[0037] Example 2

[0038] Except that the material of the film layer in step six is ZnSe, the rest is the same as example 1.

[0039] Example 3

[0040] Except for step six, where the film material is ZnS and the coating is applied using resistance heating evaporation vacuum coating, the rest is the same as in Example 1.

[0041] Example 4

[0042] Except that the film material in step six is ​​YbF3 and the coating is done by resistance heating evaporation vacuum coating, the rest is the same as in Example 1.

[0043] Comparative Example 1

[0044] Except for step four, which requires 3 hours of preparation time before coating, the rest is the same as in Example 1.

[0045] Comparative Example 2

[0046] Except for steps one through three, the rest are the same as in Example 1 (i.e., Comparative Example 2 only uses steps four through six).

[0047] The adhesion of the coatings on the chalcogenide glass lenses coated in Examples 1-4 and Comparative Examples 1-2 was tested using 3M tape.

[0048] The chalcogenide glass lens with the coating completed in Example 1 underwent three tape stretching processes without any coating peeling off.

[0049] In Example 2, the chalcogenide glass lens after coating was stretched with tape three times without any film peeling off.

[0050] The chalcogenide glass lens with the coating completed in Example 3 underwent three tape stretching processes without any coating peeling off.

[0051] The chalcogenide glass lens with the coating completed in Example 4 underwent three tape stretching processes without any coating peeling off.

[0052] Comparative Example 1 used two chalcogenide glass lenses. One chalcogenide glass lens was used to test the surface oxidation. The preparation time was 3 hours. The lens was placed in the air. After 3 hours, the surface of the chalcogenide glass lens was observed under the test light. It was found that the surface was locally white, which indicated that the surface was locally oxidized. The other chalcogenide glass lens was used to test the adhesion of the coating. After the coating of Comparative Example 1 was completed, the other chalcogenide glass lens was subjected to three tape pulls. The coating layer showed localized point-like peeling.

[0053] In Comparative Example 2, after the coating of the chalcogenide glass lens was completed, localized spot-like peeling of the coating occurred after three tape stretching processes.

[0054] Several exemplary embodiments have been described in detail above, but this document is not intended to limit itself to the explicitly disclosed combinations. Therefore, unless otherwise stated, the various features disclosed herein can be combined to form several other combinations, which are not shown for simplicity.

Claims

1. A method for improving the adhesion of chalcogenide glass coatings, characterized in that, Including the following steps: Step 1: Immerse the chalcogenide glass lens to be coated in the cleaning solution; Step 2: Wipe the surface of the soaked chalcogenide glass lens clean with degreased cotton. Step 3: Store the cleaned chalcogenide glass lens in a mixture of acetone and alcohol. Step 4: During the preparation time before coating, remove the chalcogenide glass lens from the mixed solution and clean it with ultrasonic waves. The preparation time before coating is calculated by counting back from the time when the chalcogenide glass lens is removed from the mixed solution. Step 5: Remove the ultrasonically cleaned chalcogenide glass lens and dry it with IPA. Step 6: Take out the dried IPA chalcogenide glass lens and apply a coating. in, In step one, the cleaning solution is a mixture of dish soap and pure water, with a volume ratio of dish soap to pure water of (1-2):

30. The temperature of the cleaning solution is 25°C-35°C, and the soaking time is 20-30 minutes. In step three, the mixed solution of acetone and alcohol is prepared by mixing acetone and alcohol in a volume ratio of 1:1, and the purity of both acetone and alcohol is greater than 99%. In step four, the ultrasonic cleaning sequence is: first, ultrasonic cleaning with an alkaline detergent, then ultrasonic cleaning with pure water. In step four, the alkaline detergent is AK191.

2. The method for improving the adhesion of chalcogenide glass coatings according to claim 1, characterized in that, In step one, the chalcogenide glass lens to be coated is a polished or single-point good chalcogenide glass lens.

3. The method for improving the adhesion of chalcogenide glass coatings according to claim 1, characterized in that, In step one, the detergent is selected from kitchen dishwashing liquid.

4. The method for improving the adhesion of chalcogenide glass coatings according to claim 1, characterized in that, In step two, the wiping method using degreased cotton is to wipe the lens in a cleaning solution that has been soaked in chalcogenide glass, applying a vertical downward pressure of less than 5N.

5. The method for improving the adhesion of chalcogenide glass coatings according to claim 1, characterized in that, In step four, the ultrasonic cleaning frequency is 40-60 Hz, the ultrasonic cleaning time is 2-5 minutes, and the ultrasonic cleaning temperature is 35-45°C.

6. The method for improving the adhesion of chalcogenide glass coatings according to claim 1, characterized in that, Step four, the preparation time before coating is within 2 hours.

7. The method for improving the adhesion of chalcogenide glass coatings according to claim 1, characterized in that, In step five, the heating temperature for IPA drying is 75-85°C, and the drying time is 2-4 minutes.

8. The method for improving the adhesion of chalcogenide glass coatings according to claim 1, characterized in that, In steps one through five, the chalcogenide glass lens is supported on the fixture; In step six, the coating is either vacuum evaporation coating or vacuum sputtering coating.