Laser pretreatment ceramic chip grinding method

Abstract

The invention relates to the technical field of ceramic chip treatment, and particularly discloses a laser pretreatment ceramic chip grinding method which creatively adopts a process of combining picosecond laser cutting and double-sided grinding, and a ceramic chip is subjected to ultrasonic cleaning, pretreatment, laser treatment and cleaning and then is subjected to double-sided grinding. The required treatment time is greatly shortened, and the situation that the surface of the ceramic chip cracks is avoided by adopting a mode of combining low-power picosecond laser pretreatment and high-power picosecond laser secondary treatment.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic piece processing, in particular to a laser pre-processed ceramic piece grinding method. Background Art

[0002] Surface defects of silicon nitride ceramics will have a great impact on the performance of the ceramics, including appearance, thermal conductivity, dielectric strength and voltage resistance. At present, sandblasting or double-sided grinding are generally used to process the surface of ceramics to reduce the existence of surface defects, but sandblasting has a general ability to handle bumps and pits; although the double-sided grinding process has a strong ability to handle bumps and pits, the processing time is extremely long and the time cost is high. Therefore, it is necessary to develop a surface treatment method that reduces the double-sided grinding time. Summary of the invention

[0003] The purpose of the present invention is to provide a laser pre-processed ceramic grinding method to solve the problem that the double-sided grinding process takes a long time to process the ceramic.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] A laser pre-treated ceramic chip grinding method, specifically:

[0006] Step 1: Use ultrasonic cleaning to remove oil, impurities and debris on the surface of the ceramic tile;

[0007] Step 2: Pre-treat the ceramic piece using a low-power picosecond laser;

[0008] Step 3: Use high-power picosecond laser to treat the pre-treated ceramic slice;

[0009] Step 4: Ultrasonic cleaning to remove the debris left on the surface of the ceramic tile after laser treatment;

[0010] Step 5: Double-sided grinding of the cleaned ceramic tile.

[0011] As a limitation of the present invention, in step 2, during the low-power picosecond laser pretreatment, the process parameters are: laser power 10-30 W, scanning speed 50000-80000 mm / min.

[0012] As a limitation of the present invention, in step 2, during the pretreatment of the ceramic sheet, laser is used to cut both sides of the ceramic sheet, and the cutting depth of each side is 2 to 5 um.

[0013] As a limitation of the present invention, in step 3, during the high-power picosecond laser processing, the process parameters are: laser power 30-50W, scanning speed 10000-50000mm / min.

[0014] As a limitation of the present invention, in step 3, when the ceramic piece is laser processed, the laser is used to cut both sides of the ceramic piece, and the cutting depth of each side is 15 to 20 um.

[0015] As a limitation of the present invention, in step 5, when the ceramic piece is double-sided ground, the grinding thickness is 50-60 um on both sides.

[0016] A silicon nitride ceramic sheet is processed by the grinding method.

[0017] The pretreatment described in step 2 is to pattern the surface of the tile by low power to avoid micro cracks on the surface of the tile due to direct high power.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The method provided by the present invention innovatively adopts the process of picosecond laser cutting and double-sided grinding. The picosecond laser is used to process the silicon nitride ceramic wafer. On the one hand, the surface of the ceramic wafer undergoes an oxidation reaction under the action of laser energy to generate oxides, which reduces the wear resistance; on the other hand, the surface of the ceramic wafer is ablated with fine grooves by the laser, which increases the roughness of the surface of the ceramic wafer and is beneficial to the grinding process. Compared with double-sided grinding alone, the method provided by the present invention greatly reduces the time required for surface treatment.

[0020] The method provided by the present invention combines low-power picosecond laser pretreatment with high-power picosecond laser secondary treatment. The ceramic slice is pretreated with a low-power picosecond laser before being treated with a high-power picosecond laser, thereby avoiding surface cracking of the ceramic slice due to high-power picosecond laser treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a flow chart of the grinding method described in Example 1;

[0022] Figure 2 This is a diagram of the surface state of the ceramic piece after laser treatment in Example 1;

[0023] Figure 3 This is an optical microscope image of the ceramic surface after laser treatment in Example 1;

[0024] Figure 4 This is a three-dimensional image of the surface of the ceramic tile after laser treatment in Example 1. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0026] Ceramic sheet (silicon nitride ceramic, 3.2g / cm 3 ), commercially available.

[0027] Embodiment 1: A laser pre-treated ceramic grinding method, specifically:

[0028] Step 1: Use ultrasonic cleaning to remove oil, impurities and debris on the surface of the ceramic tile;

[0029] Step 2: Use low-power picosecond laser to pre-treat the surface of the ceramic tile after ultrasonic cleaning. The cutting depth during pre-treatment is 2um on one side and double-sided cutting. The laser power is set to 10W and the scanning speed is 80000mm / min.

[0030] Step 3: Use high-power picosecond laser to process the pre-treated ceramic slice. The cutting depth during laser processing is 15um on one side and double-sided cutting. Set the laser power to 30W and the scanning speed to 50000mm / min.

[0031] Step 4: Ultrasonic cleaning to remove the debris left on the surface of the ceramic tile after laser treatment;

[0032] Step 5: Grind the cleaned ceramic tile on both sides with a grinding thickness of 50um on both sides.

[0033] Embodiment 2: A laser pre-treated ceramic grinding method, specifically:

[0034] Step 1: Use ultrasonic cleaning to remove oil, impurities and debris on the surface of the ceramic tile;

[0035] Step 2: Use low-power picosecond laser to pre-treat the surface of the ceramic tile after ultrasonic cleaning. The cutting depth during pre-treatment is 5um on one side and double-sided cutting. The laser power is set to 30W and the scanning speed is 50000mm / min.

[0036] Step 3: Use high-power picosecond laser to process the pre-treated ceramic slice. The cutting depth during laser processing is 15um on one side and double-sided cutting. Set the laser power to 30W and the scanning speed to 50000mm / min.

[0037] Step 4: Ultrasonic cleaning to remove the debris left on the surface of the ceramic tile after laser treatment;

[0038] Step 5: Grind the cleaned ceramic tile on both sides with a grinding thickness of 50um on both sides.

[0039] Embodiment 3: A laser pre-treated ceramic tile grinding method, specifically:

[0040] Step 1: Use ultrasonic cleaning to remove oil, impurities and debris on the surface of the ceramic tile;

[0041] Step 2: Use low-power picosecond laser to pre-treat the surface of the ceramic tile after ultrasonic cleaning. The cutting depth during pre-treatment is 2um on one side and double-sided cutting. The laser power is set to 10W and the scanning speed is 80000mm / min.

[0042] Step 3: Use high-power picosecond laser to process the pre-treated ceramic slice. The cutting depth during laser processing is 20um on one side and double-sided cutting. Set the laser power to 50W and the scanning speed to 10000mm / min.

[0043] Step 4: Ultrasonic cleaning to remove the debris left on the surface of the ceramic tile after laser treatment;

[0044] Step 5: Grind the cleaned ceramic tile on both sides with a grinding thickness of 60um on both sides.

[0045] Embodiment 4: A laser pre-treated ceramic grinding method, specifically:

[0046] Step 1: Use ultrasonic cleaning to remove oil, impurities and debris on the surface of the ceramic tile;

[0047] Step 2: Use low-power picosecond laser to pre-treat the surface of the ceramic tile after ultrasonic cleaning. The cutting depth during pre-treatment is 5um on one side and double-sided cutting. The laser power is set to 30W and the scanning speed is 50000mm / min.

[0048] Step 3: Use high-power picosecond laser to process the pre-treated ceramic slice. The cutting depth during laser processing is 20um on one side and double-sided cutting. Set the laser power to 50W and the scanning speed to 10000mm / min.

[0049] Step 4: Ultrasonic cleaning to remove the debris left on the surface of the ceramic tile after laser treatment;

[0050] Step 5: Grind the cleaned ceramic tile on both sides with a grinding thickness of 60um on both sides.

[0051] Embodiment 5: A laser pre-treated ceramic grinding method, specifically:

[0052] Step 1: Use ultrasonic cleaning to remove oil, impurities and debris on the surface of the ceramic tile;

[0053] Step 2: Use low-power picosecond laser to pre-treat the surface of the ceramic tile after ultrasonic cleaning. The cutting depth during pre-treatment is 3um on one side and double-sided cutting. The laser power is set to 20W and the scanning speed is 70000mm / min.

[0054] Step 3: Use high-power picosecond laser to process the pre-treated ceramic slice. The cutting depth during laser processing is 18um on one side and double-sided cutting. Set the laser power to 40W and the scanning speed to 25000mm / min.

[0055] Step 4: Ultrasonic cleaning to remove the debris left on the surface of the ceramic tile after laser treatment;

[0056] Step 5: Grind the cleaned ceramic tile on both sides with a grinding thickness of 60um on both sides.

[0057] Embodiment 6: A laser pre-treated ceramic grinding method, specifically:

[0058] Step 1: Use ultrasonic cleaning to remove oil, impurities and debris on the surface of the ceramic tile;

[0059] Step 2: Use low-power picosecond laser to pre-treat the surface of the ceramic tile after ultrasonic cleaning. The cutting depth during pre-treatment is 3um on one side and double-sided cutting. The laser power is set to 20W and the scanning speed is 70000mm / min.

[0060] Step 3: Use high-power picosecond laser to process the pre-treated ceramic slice. The cutting depth during laser processing is 15um on one side and double-sided cutting. Set the laser power to 30W and the scanning speed to 50000mm / min.

[0061] Step 4: Ultrasonic cleaning to remove the debris left on the surface of the ceramic tile after laser treatment;

[0062] Step 5: Grind the cleaned ceramic tile on both sides with a grinding thickness of 50um on both sides.

[0063] Embodiment 7: A laser pre-treated ceramic grinding method, specifically:

[0064] Step 1: Use ultrasonic cleaning to remove oil, impurities and debris on the surface of the ceramic tile;

[0065] Step 2: Use low-power picosecond laser to pre-treat the surface of the ceramic tile after ultrasonic cleaning. The cutting depth during pre-treatment is 3um on one side and double-sided cutting. The laser power is set to 20W and the scanning speed is 70000mm / min.

[0066] Step 3: Use high-power picosecond laser to process the pre-treated ceramic slice. The cutting depth during laser processing is 20um on one side and double-sided cutting. Set the laser power to 50W and the scanning speed to 10000mm / min.

[0067] Step 4: Ultrasonic cleaning to remove the debris left on the surface of the ceramic tile after laser treatment;

[0068] Step 5: Grind the cleaned ceramic tile on both sides with a grinding thickness of 50um on both sides.

[0069] Based on Example 1, a control experiment was carried out below, and specifically Comparative Example 1 is as follows:

[0070] Comparative Example 1: This comparative example relates to a laser pre-treated ceramic grinding method, which is different from Example 1 in that low-power picosecond laser is not used for pre-treatment, specifically:

[0071] Step 1: Use ultrasonic cleaning to remove oil, impurities and debris on the surface of the ceramic tile;

[0072] Step 3: Use high-power picosecond laser to process the ultrasonically cleaned ceramic slice. The cutting depth during laser processing is 15um on one side and double-sided cutting. Set the laser power to 30W and the scanning speed to 50000mm / min.

[0073] Step 4: Ultrasonic cleaning to remove the debris left on the surface of the ceramic tile after laser treatment;

[0074] Step 5: Grind the cleaned ceramic tile on both sides with a grinding thickness of 50um on both sides.

[0075] Testing experiment: Silicon nitride ceramic wafers of the same batch and specification were selected, and ceramic wafers for testing were processed according to the processing techniques in Example 1, Example 2, Example 3, Example 4, Example 5, Example 6, Example 7, and Comparative Example 1, and ceramic wafers that were only double-sided polished (polishing thickness: 50um on both sides) were used as Comparative Example 2 to test the performance of the ceramic wafers.

[0076] Thermal conductivity test: According to the "Flash Method for Measurement of Thermal Diffusivity or Thermal Conductivity" (GB / T22588-2008), a laser thermal conductivity meter (LFA 427) was used to test the thermal conductivity of each tile. The tile was ground, polished, and cleaned with deionized water. It was dried in an oven at 100°C for 4 hours. The test temperature was set to 25°C. The tile was placed on the sample holder of the laser thermal conductivity meter. The laser thermal conductivity meter was started to irradiate the laser to the tile surface. The thermal diffusivity of the tile was quickly measured. Then, the specific heat value of the silicon nitride tile (0.68 J·g -1 ·K -1 ), and thus calculate the thermal conductivity of the ceramic at room temperature.

[0077] Dielectric property test: After processing the ceramic piece into a sample of 22.7mm×10.0mm in size, a vector network analyzer was used to test the dielectric constant and dielectric loss of the sample at 8.2-12.4GHz in the X-band, with 128 sample points and an error setting of 0.005.

[0078]

[0079] Conclusion: It can be seen from the test data that the thermal conductivity and dielectric constant of the silicon nitride ceramic sheet processed by the processing technology of Example 1 are better than those of the ceramic sheets of Comparative Examples 1 and Comparative Examples 2. Compared with Example 1, Comparative Example 1 did not undergo low-power picosecond laser pretreatment, which resulted in tiny cracks on the surface of the ceramic sheet, which in turn affected the thermal conductivity, dielectric constant and voltage resistance of the ceramic sheet. Comparative Example 2 is a silicon nitride ceramic sheet that has undergone double-sided grinding. Compared with Example 1, its thermal conductivity, dielectric constant and voltage resistance are not as good as those of the ceramic sheet processed by the processing technology of Example 1. When processing the ceramic sheet of Comparative Example 2, the grinding time required is longer than that of Example 1. Therefore, the laser pretreatment ceramic sheet grinding method provided by the present invention can solve the problem of the extremely long time required for the double-sided grinding process of silicon nitride ceramic sheets, and the processed silicon nitride ceramic sheets have excellent performance.

[0080] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A laser pre-treated ceramic grinding method, characterized in that: Specifically: Step 1: Use ultrasonic cleaning to remove oil, impurities and debris on the surface of the ceramic tile; Step 2: Pre-treat the ceramic piece using a low-power picosecond laser; Step 3: Use high-power picosecond laser to treat the pre-treated ceramic slice; Step 4: Ultrasonic cleaning to remove the debris left on the surface of the ceramic tile after laser treatment; Step 5: Double-sided grinding of the cleaned ceramic tile.

2. A laser pre-treated ceramic grinding method according to claim 1, characterized in that: In step 2, during the low-power picosecond laser pretreatment, the process parameters are: laser power 10-30W, scanning speed 50000-80000mm / min.

3. A laser pre-treated ceramic grinding method according to claim 1, characterized in that: In the step 2, during the pretreatment of the ceramic sheet, laser is used to cut both sides of the ceramic sheet, and the cutting depth of each side is 2 to 5 um.

4. The laser pre-treated ceramic grinding method according to claim 1, characterized in that: In step 3, during high-power picosecond laser processing, the process parameters are: laser power 30-50W, scanning speed 10000-50000mm / min.

5. The laser pre-treated ceramic grinding method according to claim 1, characterized in that: In step 3, when the ceramic piece is laser processed, the laser is used to cut both sides of the ceramic piece, and the cutting depth of each side is 15 to 20 um.

6. The laser pre-treated ceramic grinding method according to claim 1, characterized in that: In step 5, when the ceramic piece is double-sided ground, the grinding thickness is 50-60 um on both sides.

7. A silicon nitride ceramic sheet processed by the grinding method according to claims 1 to 6.

Images