CN110316970A - The preparation method of ultra-thin quartz glass piece - Google Patents

Abstract

The invention provides a method for preparing an ultra-thin quartz glass sheet. The method combines precision mechanical polishing and acid etching to prepare an ultra-thin quartz glass sheet; its thickness is ≤100 μm, the thickness uniformity is -2 μm to 2 μm, and the surface roughness Ra≤2nm; the method includes the following steps: using Precision mechanical polishing: Grinding and polishing the quartz glass sheet to obtain the first quartz glass sheet; cleaning; acid etching to obtain an ultra-thin quartz glass sheet; the acid etching uses hydrofluoric acid with a concentration of 10-20mol/L , the acid etching temperature is 30° C. to 40° C., and the acid etching rate is ≤1 μm/min. The method combines precision mechanical polishing and hydrofluoric acid etching to process the quartz glass sheet, and by matching and coordinating the process parameters of each process, the fragmentation of the quartz glass sheet in the preparation process is avoided, and its thickness uniformity is improved at the same time And surface roughness, which is more suitable for practical use.

Description

Preparation method of ultra-thin quartz glass sheet

technical field

The invention belongs to the field of ultra-thin quartz glass sheet manufacturing, and particularly relates to a preparation method of an ultra-thin quartz glass sheet with a thickness ≤ 100 μm, a thickness uniformity of -2 μm to 2 μm and a surface roughness Ra ≤ 2 nm.

Background technique

Ultra-thin sheets of quartz glass can be used as high-frequency circuit substrates for fabricating microcircuits on their surfaces. With the development of science and technology, the frequency band is gradually increased from microwave, millimeter wave, and terahertz wave, which put forward higher requirements for the thickness uniformity and surface roughness of high-frequency circuit substrates.

Mechanical grinding and polishing is the most commonly used optical method for processing optical materials such as quartz glass, sapphire and crystal. This method makes the glass surface smooth and reduces the surface roughness of the glass by physical polishing. However, the thickness limit of the quartz glass sheet obtained by mechanical grinding and polishing is about 0.2 mm. Since quartz glass is a brittle material, if it continues to be thinned by mechanical methods, there will be problems such as fragmentation of quartz glass sheets and uneven thickness during processing.

Contents of the invention

The main purpose of the present invention is to provide a method for preparing an ultra-thin quartz glass sheet with thickness≤100μm, thickness uniformity of -2μm～2μm and surface roughness Ra≤2nm. The method combined with hydrofluoric acid etching processes the matching and coordination of process parameters in each process of quartz glass sheet, avoids fragmentation in the preparation process of quartz glass sheet, and improves its thickness uniformity and surface roughness at the same time, so that it is more suitable for practical use.

The purpose of the present invention and the solution to its technical problems are achieved by adopting the following technical solutions. According to the preparation method of an ultra-thin quartz glass sheet proposed by the present invention, the method of combining precision mechanical polishing and acid etching is used to prepare an ultra-thin quartz glass sheet; the thickness of the ultra-thin quartz glass sheet is ≤100 μm, and the thickness is uniform The resistance is -2μm～2μm, and the surface roughness Ra≤2nm.

The purpose of the present invention and its technical problems can also be further realized by adopting the following technical measures.

Preferably, the preparation method of the aforementioned ultra-thin quartz glass sheet, wherein said preparation method comprises the following steps:

1) Grinding and polishing the quartz glass sheet by precision mechanical polishing to obtain the first quartz glass sheet;

2) cleaning;

3) Acid etching to obtain an ultra-thin quartz glass sheet.

Preferably, the preparation method of the aforementioned ultra-thin quartz glass sheet, wherein said step 1) comprises the following steps:

Abrasives are used to grind the quartz glass sheet on both sides to a specified thickness; polishing powder is used to polish the quartz glass sheet on both sides to obtain the first quartz glass sheet.

Preferably, in the aforementioned method for preparing an ultra-thin quartz glass sheet, the abrasive is selected from Al ₂ O ₃ particles with a particle size of ≤10 μm; the polishing powder is selected from SiO ₂ particles with a particle size of ≤100 nm.

Preferably, in the aforementioned method for preparing an ultra-thin quartz glass sheet, nodular cast iron is used as the grinding medium for the grinding; polyurethane is used as the polishing medium for the polishing.

Preferably, in the aforementioned method for preparing an ultra-thin quartz glass sheet, the thickness of the first quartz glass sheet is 0.2-0.3 mm, the thickness uniformity is -5 μm-5 μm, and the surface roughness Ra≤1 nm.

Preferably, the aforementioned method for preparing an ultra-thin quartz glass sheet, wherein the cleaning includes the following steps: soaking the first quartz glass sheet with a hydrofluoric acid solution; and then performing ultrasonic cleaning.

Preferably, in the aforementioned method for preparing ultra-thin quartz glass sheets, the mass concentration of the hydrofluoric acid solution is 0.2-1%, the immersion temperature is 20-30°C, and the immersion time is 2min-5min.

Preferably, in the aforementioned method for preparing an ultra-thin quartz glass sheet, the liquid used in the ultrasonic cleaning is deionized water with a resistivity ≥ 18 MΩ·cm and an ultrasonic frequency of 28-45 kHz.

Preferably, the aforementioned method for preparing an ultra-thin quartz glass sheet, wherein the acid etching uses hydrofluoric acid, the concentration of which is 10-20 mol/L; the temperature of the acid etching is 30°C-40°C; The acid etching rate is ≤1 μm/min.

By means of the above-mentioned technical scheme, a method for preparing an ultra-thin quartz glass sheet proposed by the present invention has at least the following advantages:

1. The preparation method of the ultra-thin quartz glass sheet proposed by the present invention combines the methods of precision mechanical polishing and acid etching, which combines the advantages of mechanical processing and chemical etching processing. First, the surface roughness of the glass is guaranteed by precision mechanical grinding and polishing , and then thinned to the micron level by hydrofluoric acid etching, and finally prepared an ultra-thin quartz glass sheet with a thickness of ≤100 μm, a thickness uniformity of -2 μm to 2 μm, and a surface roughness of Ra≤2nm;

2. The preparation method of the ultra-thin quartz glass sheet proposed by the present invention is to process the quartz glass sheet to a thickness of 200-300 μm by mechanical processing, and then reduce its thickness to ≤ The target thickness is 100μm; when hydrofluoric acid etching is used to thin the quartz glass sheet, the quartz glass sheet is placed in the hydrofluoric acid solution with a special jig, and there is no mechanical external force during the etching process, which can avoid the fragmentation of the sheet and overcome Solved the problems of fragmentation and non-uniform thickness of the quartz glass sheet that occurred when the quartz glass sheet was continuously thinned by mechanical methods due to the brittleness of the quartz glass sheet itself;

3. Hydrofluoric acid etching and processing of quartz glass is mainly used for the production of quartz glass devices, which can etch holes, micro-grooves and other shapes on the glass; the principle is that hydrofluoric acid and quartz glass can undergo chemical reactions, However, this processing method easily exposes the subsurface defects of the glass polishing surface, causing the surface roughness of the glass to increase; the preparation method of the ultra-thin quartz glass sheet proposed by the present invention, by using precision mechanical polishing, controls the grinding of the abrasive material and polishing powder. The material and particle size, as well as the process parameters of grinding and polishing, make the surface roughness of the first quartz glass sheet reach the level of Ra≤1nm; Defects with large surface roughness in the etching process. The surface roughness Ra of the ultra-thin quartz glass sheet processed by the technical scheme of the invention is less than or equal to 2nm, which can meet the use requirements of high-frequency circuit substrates.

The above description is only an overview of the technical solutions of the present invention. In order to understand the technical means of the present invention more clearly and implement them according to the contents of the description, the preferred embodiments of the present invention will be described in detail below.

Detailed ways

In order to further elaborate the technical means and effects adopted by the present invention to achieve the intended purpose of the invention, below in conjunction with preferred embodiments, a method for preparing an ultra-thin quartz glass sheet proposed according to the present invention, its specific implementation, structure, Features and their functions are described in detail below.

The present invention proposes a method for preparing an ultra-thin quartz glass sheet, which combines precision mechanical polishing and acid etching to prepare an ultra-thin quartz glass sheet; the thickness of the ultra-thin quartz glass sheet is ≤100 μm, and the thickness uniformity is -2μm～2μm, surface roughness Ra≤2nm.

Grinding and polishing is a surface processing process to obtain glass of required size and surface quality. Precision mechanical grinding and polishing will be more finely controlled than mechanical grinding and polishing. For ultra-thin sheets, precision mechanical polishing is to obtain good thickness uniformity and surface roughness, and hydrofluoric acid etching is to reduce the thickness to less than 100 μm; neither method alone can achieve the thickness ≦100μm, thickness uniformity of -2μm～2μm, and ultra-thin sheet processing with surface roughness≦2nm.

Before the quartz glass sheet of the present invention is ground, the quartz glass sheet needs to be pretreated first, and the thickness of the quartz glass sheet is about 400 μm by plane grinding or coarse grinding. Then, use the above-mentioned method to process it. The surface roughness of the quartz glass sheet is ensured by precise mechanical polishing, and then the thickness of the quartz glass sheet is thinned by hydrofluoric acid etching, so that the quartz glass sheet is thinned to the micron level to obtain an ultra-thin quartz glass sheet.

Preferably, the preparation method of the aforementioned ultra-thin quartz glass sheet comprises the following steps:

1) Grinding and polishing the quartz glass sheet by precision mechanical polishing to obtain the first quartz glass sheet;

2) cleaning;

3) Acid etching to obtain an ultra-thin quartz glass sheet.

Preferably, the aforementioned method for preparing an ultra-thin quartz glass sheet, wherein said step 1) includes the following steps: using abrasives to grind the quartz glass sheet on both sides to a specified thickness; using polishing powder to polish the quartz glass sheet on both sides to obtain the first Quartz glass sheet.

The grinding is done mechanically, and the abrasive grain size used is also coarser than that used for polishing; the main difference between the two is that the surface smoothness that can be achieved by polishing is higher than that achieved by grinding. The above mentioned grinding and polishing can be realized on the same plane polishing machine, but the configurations and consumables of the two are different.

Preferably, in the aforementioned method for preparing an ultra-thin quartz glass sheet, the abrasive is selected from Al ₂ O ₃ particles with a particle size of ≤10 μm; the polishing powder is selected from SiO ₂ particles with a particle size of ≤100 nm.

Both the grinding and polishing can change the dimensional accuracy of the quartz glass sheet; the technical solution of the present invention adopts the process of first grinding and then polishing. Both grinding and polishing are carried out in the thickness direction of the quartz glass sheet. Due to the large particle size of the grinding abrasive, its thickness removal rate is greater than that of polishing. Grinding is a necessary procedure for polishing; while polishing is to smooth the surface of the quartz glass sheet while reducing the thickness of the quartz glass sheet.

During polishing, the rotating polishing wheel presses against the quartz glass sheet, so that the polishing powder rolls and micro-cuts the surface of the quartz glass sheet, thereby obtaining a bright processed surface, and the surface roughness can generally reach the nanometer level.

Preferably, in the aforementioned method for preparing an ultra-thin quartz glass sheet, nodular cast iron is used as the grinding medium for the grinding; polyurethane is used as the polishing medium for the polishing.

Grinding medium and polishing medium described in the present invention refer to the grinding wheel that is fixed on the precision mechanical polishing machine, through the motion of grinding wheel, push described abrasive material and polishing powder to move on the quartz glass sheet surface respectively, through abrasive material and polishing The circulating flow of the powder realizes the grinding and polishing of the surface of the quartz glass sheet.

Preferably, in the aforementioned method for preparing an ultra-thin quartz glass sheet, the thickness of the first quartz glass sheet is 0.2-0.3 mm, the thickness uniformity is -5 μm-5 μm, and the surface roughness Ra≤1 nm.

The thickness uniformity refers to the thickness value difference between any two points on the ultra-thin substrate; the smaller the absolute value of the thickness uniformity, the better the thickness uniformity of the substrate.

The surface roughness (sμrface roμghness) is represented by Ra, which refers to the small spacing and the unevenness of the tiny peaks and valleys on the processed surface, and the distance (wave distance) between the two peaks or two troughs is very small (at 1mm Below), it belongs to the micro-geometry error. The smaller the surface roughness of a material, the smoother the surface.

Preferably, the aforementioned method for preparing an ultra-thin quartz glass sheet, wherein the cleaning includes the following steps: soaking the first quartz glass sheet with a hydrofluoric acid solution; and then performing ultrasonic cleaning.

The ultrasonic cleaning is to use the cavitation, acceleration and direct flow of ultrasonic waves in the liquid to directly and indirectly affect the liquid and dirt, so that the dirt layer is dispersed, emulsified and peeled off to achieve the purpose of cleaning.

Carry out acid solution immersion and ultrasonic cleaning in sequence according to the above steps. Described acid solution immersion is aimed at the SiO remaining on the surface of the first quartz glass polishing disc _The polishing powder particles react and dissolve; the purpose of the ultrasonic cleaning is to remove the residual polishing powder on the surface of the first quartz glass disc for precision polishing, and remove the polishing powder. Dust particles on glass surface.

Preferably, in the aforementioned method for preparing ultra-thin quartz glass sheets, the mass concentration of the hydrofluoric acid solution is 0.2-1%, the immersion temperature is 20-30°C, and the immersion time is 2min-5min.

Preferably, in the aforementioned method for preparing an ultra-thin quartz glass sheet, the liquid used in the ultrasonic cleaning is deionized water with a resistivity ≥ 18 MΩ·cm and an ultrasonic frequency of 28-45 kHz.

Preferably, the aforementioned method for preparing an ultra-thin quartz glass sheet, wherein the acid etching uses hydrofluoric acid, the concentration of which is 10-20 mol/L; the temperature of the acid etching is 30°C-40°C; The acid etching rate is ≤1 μm/min.

The above acid etching thinning process ensures that the quartz glass sheet can be etched and thinned by hydrofluoric acid at an appropriate rate by controlling the concentration of hydrofluoric acid and etching temperature and other process parameters, so that the hydrofluoric acid can be uniformly Etching the first quartz glass sheet until the thickness of the quartz glass sheet is reduced to a specified thickness. Through the control of the acid etching process, the thickness uniformity of the quartz glass sheet will be further improved.

The above process of hydrofluoric acid etching to thin the quartz glass sheet is to place the quartz glass sheet in the hydrofluoric acid solution with a special clamp. During this etching process, the described quartz glass sheet will not be affected by Any mechanical external force, thus avoiding the problem that the quartz glass flakes are easily broken.

Further description will be given below through more specific examples.

Example 1

The present invention proposes a kind of preparation method of ultra-thin quartz glass sheet, comprises the following steps:

1) Rough processing of quartz glass sheet: before grinding, the quartz glass sheet is ground or roughly ground, and its thickness is controlled to be 0.4mm;

2) Precision mechanical grinding and polishing: use nodular cast iron as the grinding medium, and Al2O3 particles with a particle size of 10 μm are used as the abrasive for double-sided grinding, and the thickness of the removed quartz glass sheet is 80-170 μm; polyurethane is used as the polishing medium, and the particle size is 50-100nm. SiO2 particles are used as polishing powder for double-sided polishing, and the thickness of the removed quartz glass sheet is 20 to 30 μm; through this step, the quartz glass sheet is processed to a thickness of 0.2 to 0.3 mm, with a thickness uniformity of -5 μm to 5 μm, and a rough surface The first quartz glass polished piece with Ra≤1nm;

Cleaning: First soak the first quartz glass polishing sheet at 20°C with a hydrofluoric acid aqueous solution with a mass concentration of 0.5% for 5 minutes; then ultrasonically clean it, the ultrasonic cleaning uses water as the medium, and its resistivity ≥ 18MΩ·cm, ultrasonic frequency is 45kHz;

Thinning by acid etching: a hydrofluoric acid solution with a concentration of 15 mol/ was prepared, the etching temperature was set at 35° C., and the measured etching rate (removal rate on both sides) was 0.8 μm/min. During the acid etching process, the quartz glass sheet is placed horizontally, and the acid solution is pumped and circulated from top to bottom.

It takes about 5 hours to etch the first quartz glass sheet with a thickness of 300 μm to 50 μm.

The thickness uniformity of the ultra-thin quartz glass sheet prepared in this embodiment is -2 μm to 2 μm, and the surface roughness is Ra=2nm.

Example 2-6

Step is with embodiment 1.

The process parameters of each embodiment were adjusted according to the data in Table 1 below, and the dimensions of the prepared ultra-thin quartz glass sheets are shown in Table 1.

Table 1 Process parameters and product performance of Examples 1-6

As can be seen from the process parameters of Examples 1 to 6 shown in the above Table 1 and the performance data of the prepared products, the technical solution of the present invention uses a combination of precision mechanical polishing and hydrofluoric acid etching to process quartz glass Through the matching and coordination of process parameters in each process, the fragmentation of quartz glass flakes during the preparation process is avoided, and the thickness uniformity and surface roughness of ultra-thin quartz glass flakes are also improved. The prepared ultra-thin quartz glass sheet has a thickness of ≤100 μm, a thickness uniformity of -2 μm to 2 μm and a surface roughness Ra of 2 nm, which can meet the use requirements of high-frequency circuit substrates.

The technical features in the claims of the present invention and/or the description can be combined, and the combination is not limited to the combination obtained by reference in the claims. The technical solution obtained by combining the technical features in the claims and/or the description is also within the protection scope of the present invention.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still belong to the present invention. within the scope of the technical solution of the invention.

Claims (10)

1. A preparation method for an ultra-thin quartz glass sheet, characterized in that, Combined use of precision mechanical polishing and acid etching to prepare ultra-thin quartz glass sheets; The thickness of the ultra-thin quartz glass sheet is less than or equal to 100 μm, the thickness uniformity is -2 μm to 2 μm, and the surface roughness Ra is less than or equal to 2 nm. 2. the preparation method of ultra-thin quartz glass sheet according to claim 1, is characterized in that, it comprises the following steps: 1) Grinding and polishing the quartz glass sheet by precision mechanical polishing to obtain the first quartz glass sheet; 2) cleaning; 3) Acid etching to obtain an ultra-thin quartz glass sheet. 3. the preparation method of ultra-thin quartz glass sheet according to claim 2, is characterized in that, described step 1) comprises the following steps: Abrasives are used to grind the quartz glass sheet on both sides to a specified thickness; polishing powder is used to polish the quartz glass sheet on both sides to obtain the first quartz glass sheet. 4. the preparation method of ultra-thin quartz glass sheet according to claim 3, is characterized in that, The abrasive is selected from Al ₂ O ₃ particles with a particle size of ≤10 μm; the polishing powder is selected from SiO ₂ particles with a particle size of ≤100 nm. 5. the preparation method of ultra-thin quartz glass sheet according to claim 2, is characterized in that, The grinding uses ductile iron as the grinding medium; the polishing uses polyurethane as the polishing medium. 6. according to the preparation method of the ultra-thin quartz glass sheet described in any one of claim 2-5, it is characterized in that, The thickness of the first quartz glass sheet is 0.2-0.3mm, the thickness uniformity is -5μm-5μm, and the surface roughness Ra≤1nm. 7. the preparation method of ultra-thin quartz glass sheet according to claim 6, is characterized in that, Described cleaning comprises the following steps: Soak the first quartz glass sheet with hydrofluoric acid solution; then perform ultrasonic cleaning. 8. the preparation method of ultra-thin quartz glass sheet according to claim 7, is characterized in that, The mass concentration of the hydrofluoric acid solution is 0.2-1%, the soaking temperature is 20-30°C, and the soaking time is 2min-5min. 9. the preparation method of ultra-thin quartz glass sheet according to claim 7, is characterized in that, The liquid used in the ultrasonic cleaning is deionized water, the resistivity of which is ≥18MΩ·cm, and the ultrasonic frequency is 28-45kHz. 10. the preparation method of ultra-thin quartz glass sheet according to claim 6, is characterized in that, Described acid etching adopts hydrofluoric acid, and its concentration is 10～20mol/L; The temperature of the acid etching is 30°C to 40°C; The acid etching rate is ≤1 μm/min.