Edge trimming and debinding method for green body of electronic ceramic

Abstract

The present invention discloses a method for edge wrapping and debinding of green bodies of electronic ceramics, which relates to the technical field of electronic ceramic processing. The present invention adopts a debinding method with aluminum foil edge wrapping. The green bodies of electronic ceramics are stacked in a debinding fixture according to specified layers. Aluminum foil with a certain thickness is cut into specified dimensions and heat-treated for a period of time. The heat-treated aluminum foil is used to wrap the whole four sides of the fixture and the green bodies, and the edge wrapping area occupies a certain proportion of the area of the fixture. After the edge wrapping is completed, the green bodies and the fixture with edge wrapping are loaded into a debinding furnace for debinding in an atmosphere of air or nitrogen. After debinding and taking out of the furnace, the edge wrapping is removed, and finally, a flat, non-warped, non-cracked, and non-blackened electronic ceramic debinding sheet is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic ceramic processing, and specifically to a method for edge wrapping and debinding of green bodies of electronic ceramics. Background Art

[0002] For electronic ceramics such as alumina, aluminum nitride, silicon nitride, and silicon carbide ceramics, their preparation generally includes green body forming and green body sintering. Currently, the commonly used green body forming methods include dry pressing forming, injection molding, tape casting, rolling film forming, etc. Among them, tape casting is widely used because its process is easier to control and the product quality is stable. The tape casting process mainly includes the preparation of the slurry in the early stage and the adjustment of the process parameters in the later stage. The preparation of the tape casting slurry plays a decisive role in the entire tape casting process. The main components of the tape casting slurry are inorganic powder and organic carrier. Among them, the inorganic powder acts as the functional phase, and the organic carrier acts as the mobile phase.

[0003] The organic carrier of the tape casting slurry mainly includes solvent, dispersant, binder, plasticizer, and other modifiers. As the only continuous phase in the green body, the type and content of the binder determine the strength and density of the final green body. Currently, the most commonly used binders in the tape casting slurry are mainly two types: PVB (polyvinyl butyral) and PMMA (polymethyl methacrylate). PVB has the advantages of good compatibility, high plasticity, and easy debinding, and is the most commonly used tape casting binder.

[0004] Before sintering, the green bodies of silicon nitride, aluminum nitride, and silicon carbide must undergo debinding. Currently, the debinding method used for ceramic green bodies is basically to stack them in a debinding fixture for debinding. The edges of the green bodies are completely exposed to the outside, which will cause two problems. One is that the debinding rate at the edges of the green bodies is faster than that in the middle, and the other is that the heat dissipation at the edges of the green bodies is more than that in the middle, resulting in uneven heating of the entire green body. These two problems will both cause the debinding film to warp and the debinding film to be easily broken, thereby causing product scrapping and a decrease in the yield. The solutions of the prior art have two directions. One is to reduce the stacking layer number of the green bodies, and the other is to adjust the debinding process or the debinding time. Both of these directions will cause a decrease in production capacity, and the difficulty and investment in adjusting the debinding process are very large.

[0005] Therefore, developing a debinding method for green bodies of electronic ceramics such as silicon nitride, aluminum nitride, and silicon carbide is an urgent problem to be solved in the field of electronic ceramic preparation at present. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for edge wrapping and debinding of green bodies of electronic ceramics to solve the problems proposed in the prior art.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A method for edge wrapping and debinding of green bodies of electronic ceramics includes the following steps:

[0009] Step 1: Place the green body of electronic ceramics inside the debinding fixture in a stacked manner;

[0010] Step 2: Cut the aluminum foil, perform heat treatment, and set it aside for later use;

[0011] Step 3: Take the aluminum foil after heat treatment in Step 2 and perform edge wrapping on the entire debinding fixture and the green body of electronic ceramics in Step 1;

[0012] Step 4: Load the entire debinding fixture and the green body with the edge wrapping completed in Step 3 into the debinding furnace and perform atmosphere debinding;

[0013] Step 5: After the atmosphere debinding is completed, remove the edge wrapping to obtain the debound sheet.

[0014] Further, 8 - 15 green bodies of electronic ceramics can be stacked inside the debinding fixture in Step 1, and each green body is separated by spraying boron nitride powder for separation during firing.

[0015] Further, the green body of electronic ceramics is one of the green bodies of silicon nitride, aluminum nitride, alumina, silicon carbide, and silicon powder ceramics.

[0016] Further, in Step 2, the thickness of the aluminum foil is 15 - 30 μm, the length is 900 - 1100 mm, and the width is 55 - 65 mm.

[0017] Further, the heat treatment in Step 2 is carried out at 300 °C for 1 - 3 h.

[0018] Further, the edge wrapping treatment in Step 3 is specifically: the aluminum foil wraps the side edges, and the proportion of the aluminum foil covering the upper and lower bottom areas is 1 / 4 - 1 / 3.

[0019] Further, the atmosphere debinding in Step 4 includes the following 5 debinding stages:

[0020] Stage 1: Introduce air or nitrogen atmosphere into the debinding furnace. According to the volume of each 500 L of the furnace body, set the atmosphere flow rate to 200 - 800 L / min, and heat up to 200 - 240 °C at a rate of 0.4 °C / min, and hold for 50 - 100 min;

[0021] Stage 2: After the insulation in Stage 1 is completed, adjust the atmosphere flow rate to 20 - 100 L / min, continue to heat up at a rate of 0.4 - 0.6 °C / min, and hold for 20 - 30 min every time the temperature rises by 50 - 60 °C;

[0022] Stage 3: When the temperature in Stage 2 rises to 350 - 370 °C, adjust the atmosphere flow rate to 20 - 100 L / min, continue to heat up at a rate of 0.4 - 0.6 °C / min, and hold for 60 - 80 min every time the temperature rises by 50 - 60 °C;

[0023] Stage 4: When the temperature in Stage 3 rises to 500 - 550 °C, adjust the atmosphere flow rate to 20 - 100 L / min, and cool down at a rate of 0.6 - 2 °C / min;

[0024] Stage 5: When the temperature in Stage 4 drops to 400 - 450 °C, adjust the atmosphere flow rate to 60 - 300 L / min, keep it warm for 2 - 5 h, and then cool down to 20 - 25 °C at a rate of 0.5 - 5 °C / min.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] 1. Pioneeringly use the method of wrapping the edge with aluminum foil for degumming of green bodies of electronic ceramics; as a metal, aluminum foil has good thermal conductivity. Selecting aluminum foil to wrap the edge can make the temperature of the edge and the middle of the green body and the fixture uniform, so that the degumming rate of the edge and the middle of the green body tends to be consistent, effectively reducing the probability of warping, cracking and other phenomena of the degummed film; in addition, aluminum foil is recyclable and can be reused during the degumming production process; it is loaded into the degumming furnace together with the ceramic green body and the degumming fixture to optimize the degumming process, and effectively reduce energy consumption while ensuring complete degumming.

[0027] 2. The heat treatment operation of aluminum foil can effectively prevent aluminum foil from being corroded by degumming products during the degumming process of green bodies; in addition, heat treatment can soften aluminum foil, make aluminum foil fit the degumming fixture better, and facilitate the edge wrapping operation.

[0028] 3. The present invention can effectively improve the phenomena of warping, fragmentation and blackening of degummed films in the prior art ceramic degumming without affecting production capacity, and increases the stacking layers of degummed green bodies compared with the prior art. Description of the Drawings

[0029] Figure 1 It is a schematic side view structure of the aluminum foil edge wrapping of the green body of electronic ceramics in the present invention;

[0030] Figure 2 It is a schematic front / bottom view structure of the aluminum foil edge wrapping of the green body of electronic ceramics in the present invention. Detailed Embodiments

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0032] In the experiment, the green body of silicon nitride ceramic was prepared by the following steps, including: dissolving 1 part of triethyl phosphate in 50 parts of solvent, placing it in a ball mill, after ball milling for 4 h, adding 50 parts of silicon nitride powder, 4 parts of yttrium oxide, 3 parts of magnesium oxide and 3 parts of titanium oxide, continuing to ball mill for 12 h, then adding 4 parts of polyvinyl butyral and 4 parts of plasticizer, continuing to ball mill for 12 h, carrying out vacuum stirring and defoaming for 1 h, aging for 8 h after defoaming, controlling the viscosity at 10000 - 50000 CPS, sieving and then pumping it to the head of the casting machine, after forming with a doctor blade, through hot air + bottom plate heating for composite drying, peeling off the PET base tape to obtain the green body; wherein the solvent consists of 40% isopropyl alcohol, 4% ethyl lactate, 1% dioxydimethyl ether acetate, 20% ethyl acetate and 30% butyl acetate; the plasticizer consists of dibutyl phthalate and polyethylene glycol with a mass ratio of 1:1; the silicon nitride powder consists of 90% α-silicon nitride powder and 10% β-silicon nitride powder, with a particle size D50 = 0.5 - 0.9 um.

[0033] The green body of silicon wafer ceramic was prepared by the following steps, including: dissolving 1 part of triethyl phosphate in 50 parts of solvent, placing it in a ball mill, after ball milling for 4 h, adding 50 parts of silicon wafer powder, 4 parts of yttrium oxide, 3 parts of magnesium oxide, 2.75 parts of zirconium oxide and 0.25 parts of titanium oxide, continuing to ball mill for 12 h, then adding 4 parts of polyvinyl butyral and 4 parts of plasticizer, continuing to ball mill for 12 h, carrying out vacuum stirring and defoaming for 1 h, aging for 8 h after defoaming, controlling the viscosity at 10000 - 50000 CPS, sieving and then pumping it to the head of the casting machine, after forming with a doctor blade, through hot air + bottom plate heating for composite drying, peeling off the PET base tape to obtain the green body; wherein the solvent consists of 40% isopropyl alcohol, 4% ethyl lactate, 1% dioxydimethyl ether acetate, 20% ethyl acetate and 30% butyl acetate; the plasticizer consists of dibutyl phthalate and polyethylene glycol with a mass ratio of 1:1; the silicon wafer powder consists of 90% silicon powder, 8% α-silicon nitride powder and 2% β-silicon nitride powder, and the particle size of the silicon powder D50 = 2 - 10 um.

[0034] Example 1: A method for edge trimming and debinding of a green body of electronic ceramic described in this example specifically includes the following steps:

[0035] Step 1: Take 10 green bodies of silicon nitride ceramic and stack them inside the debinding fixture, and spray boron nitride separation powder between each green body to separate them;

[0036] Step 2: Cut aluminum foil to obtain a thickness of 20 μm, a length of 1100 mm, and a width of 65 mm, place it in a muffle furnace, heat-treat it at 300 °C for 3 hours, and set aside;

[0037] Step 3: Take the aluminum foil heat-treated in Step 2 and perform edge trimming on the whole debinding fixture and the green body of electronic ceramic, in accordance with Figure 1 、 2As shown, the side is wrapped with aluminum foil, and the aluminum foil covers 1 / 4 of the upper and lower bottom areas;

[0038] Step 4: Load the debinding jig with the completed edge wrapping and the green body as a whole into the debinding furnace for atmosphere debinding;

[0039] Step 5: After the atmosphere debinding is completed, remove the edge wrapping to obtain the debound sheet.

[0040] Among them, the atmosphere debinding includes the following 5 debinding stages:

[0041] Stage 1: Introduce air atmosphere into the debinding furnace. For every 500 L of the furnace volume, set the atmosphere flow rate to 800 L / min, heat up to 200 °C at a rate of 0.4 °C / min, and hold for 100 min;

[0042] Stage 2: After the holding in Stage 1 is completed, adjust the atmosphere flow rate to 50 L / min, continue to heat up at a rate of 0.5 °C / min, and hold for 30 min for every 50 °C increase in temperature;

[0043] Stage 3: When the temperature in Stage 2 reaches 350 °C, adjust the atmosphere flow rate to 80 L / min, continue to heat up at a rate of 0.5 °C / min, and hold for 60 min for every 50 °C increase in temperature;

[0044] Stage 4: When the temperature in Stage 3 reaches 550 °C, adjust the atmosphere flow rate to 100 L / min and cool down at a rate of 2 °C / min;

[0045] Stage 5: When the temperature in Stage 4 drops to 400 °C, adjust the atmosphere flow rate to 300 L / min, hold for 2 h, and then cool down to 25 °C at a rate of 0.5 °C / min.

[0046] Example 2: A method for edge wrapping and debinding of an electronic ceramic green body according to this example specifically includes the following steps:

[0047] Step 1: Take 10 silicon nitride ceramic green bodies and stack them inside the debinding jig, and separate each green body by spraying boron nitride powder for separating during firing;

[0048] Step 2: Cut the aluminum foil to obtain a thickness of 20 μm, a length of 1100 mm, and a width of 65 mm. Place it in a muffle furnace and heat-treat it at 300 °C for 1 hour for standby;

[0049] Step 3: Take the heat-treated aluminum foil in Step 2 and perform edge wrapping on the debinding jig and the electronic ceramic green body as a whole. The side is wrapped with aluminum foil, and the aluminum foil covers 1 / 4 of the upper and lower bottom areas;

[0050] Step 4: Load the debinding jig with the completed edge wrapping and the green body as a whole into the debinding furnace for atmosphere debinding;

[0051] Step 5: After the atmosphere debinding is completed, remove the edge wrapping to obtain the debound sheet.

[0052] Among them, the atmosphere debinding includes the following 5 debinding stages:

[0053] Stage 1: Introduce air atmosphere into the debinding furnace. Set the atmosphere flow rate to 800 L / min according to every 500 L of furnace volume, heat up to 200 °C at a rate of 0.4 °C / min, and hold for 100 min.

[0054] Stage 2: After the insulation in Stage 1 is completed, adjust the atmosphere flow rate to 50 L / min, continue to heat up at a rate of 0.5 °C / min, and hold for 30 min every time the temperature rises by 50 °C.

[0055] Stage 3: When the temperature in Stage 2 rises to 350 °C, adjust the atmosphere flow rate to 80 L / min, continue to heat up at a rate of 0.5 °C / min, and hold for 60 min every time the temperature rises by 50 °C.

[0056] Stage 4: When the temperature in Stage 3 rises to 550 °C, adjust the atmosphere flow rate to 100 L / min and cool down at a rate of 2 °C / min.

[0057] Stage 5: When the temperature in Stage 4 drops to 400 °C, adjust the atmosphere flow rate to 300 L / min, hold for 2 h, and then cool down to 25 °C at a rate of 0.5 °C / min.

[0058] Example 3: A method for edge-wrapped debinding of a green body of electronic ceramics described in this example specifically includes the following steps:

[0059] Step 1: Take 10 silicon nitride ceramic green bodies and stack them inside the debinding fixture, and spray boron nitride powder for separating and burning between each green body.

[0060] Step 2: Cut aluminum foil to obtain aluminum foil with a thickness of 20 μm, a length of 1100 mm, and a width of 65 mm. Place it in a muffle furnace and heat-treat it at 300 °C for 1 hour for standby.

[0061] Step 3: Take the aluminum foil heat-treated in Step 2 and perform edge-wrapping treatment on the entire debinding fixture and the electronic ceramic green body. The aluminum foil wraps the side edges, and the proportion of the upper and lower bottom areas wrapped by the aluminum foil is 1 / 3.

[0062] Step 4: Load the entire debinding fixture and green body with edge-wrapping completed in Step 3 into the debinding furnace for atmosphere debinding.

[0063] Step 5: After the atmosphere debinding is completed, remove the edge wrapping to obtain the debound sheet.

[0064] Among them, the atmosphere debinding includes the following 5 debinding stages:

[0065] Stage 1: Introduce an air atmosphere into the debinding furnace. For every 500 L of furnace volume, set the atmosphere flow rate to 800 L / min, heat up to 200 °C at a rate of 0.4 °C / min, and hold for 100 min;

[0066] Stage 2: After the insulation in Stage 1 is completed, adjust the atmosphere flow rate to 50 L / min, continue to heat up at a rate of 0.5 °C / min, and hold for 30 min every 50 °C increase in temperature;

[0067] Stage 3: When the temperature in Stage 2 reaches 350 °C, adjust the atmosphere flow rate to 80 L / min, continue to heat up at a rate of 0.5 °C / min, and hold for 60 min every 50 °C increase in temperature;

[0068] Stage 4: When the temperature in Stage 3 reaches 550 °C, adjust the atmosphere flow rate to 100 L / min, and cool down at a rate of 2 °C / min;

[0069] Stage 5: When the temperature in Stage 4 drops to 400 °C, adjust the atmosphere flow rate to 300 L / min, hold for 2 h, and then cool down to 25 °C at a rate of 0.5 °C / min.

[0070] Example 4: A method for edge debinding of a green body of electronic ceramics described in this example specifically includes the following steps:

[0071] Step 1: Take 10 silicon ceramic green bodies and stack them inside the debinding fixture, and spray boron nitride powder for separating sintering between each green body;

[0072] Step 2: Cut aluminum foil to obtain a thickness of 20 μm, a length of 1100 mm, and a width of 65 mm. Place it in a muffle furnace and heat-treat it at 300 °C for 3 hours for later use;

[0073] Step 3: Take the aluminum foil heat-treated in Step 2 and perform an edge wrapping treatment on the entire debinding fixture and the electronic ceramic green body in Step 1. The aluminum foil wraps the side edges, and the aluminum foil covers 1 / 4 of the upper and lower bottom areas;

[0074] Step 4: Load the entire debinding fixture and the green body with the edge wrapping completed in Step 3 into the debinding furnace for atmosphere debinding;

[0075] Step 5: After the atmosphere debinding is completed, remove the edge wrapping to obtain a debound sheet.

[0076] Among them, the atmosphere debinding includes the following 5 debinding stages:

[0077] Stage 1: Introduce an air atmosphere into the debinding furnace. For every 500 L of furnace volume, set the atmosphere flow rate to 800 L / min, heat up to 200 °C at a rate of 0.4 °C / min, and hold for 100 min;

[0078] Stage 2: After the heat preservation in Stage 1 is completed, adjust the atmosphere flow rate to 50 L / min, continue heating at a rate of 0.5 °C / min, and hold for 30 min every 50 °C increase in temperature;

[0079] Stage 3: When the temperature in Stage 2 rises to 350 °C, adjust the atmosphere flow rate to 80 L / min, continue heating at a rate of 0.5 °C / min, and hold for 60 min every 50 °C increase in temperature;

[0080] Stage 4: When the temperature in Stage 3 rises to 550 °C, adjust the atmosphere flow rate to 100 L / min, and cool down at a rate of 2 °C / min;

[0081] Stage 5: When the temperature in Stage 4 drops to 400 °C, adjust the atmosphere flow rate to 300 L / min, hold for 2 h, and then cool down to 25 °C at a rate of 0.5 °C / min.

[0082] Comparative Example 1: Comparative Example 1 is based on Example 1. The difference between Comparative Example 1 and Example 1 is that the steps of edging in S2 and S3 are removed, and the specific steps are as follows:

[0083] Step 1: Take 10 pieces of silicon nitride ceramic green bodies and stack them inside the debinding fixture, and spray boron nitride separation powder between each green body;

[0084] Step 2: Load the debinding fixture and the green bodies in Step 1 into the debinding furnace as a whole for atmosphere debinding;

[0085] Step 3: After the atmosphere debinding is completed, obtain the debound sheets.

[0086] The atmosphere debinding includes the following 5 debinding stages:

[0087] Stage 1: Introduce air atmosphere into the debinding furnace. According to every 500 L of the furnace volume, set the atmosphere flow rate to 800 L / min, heat up to 200 °C at a rate of 0.4 °C / min, and hold for 100 min;

[0088] Stage 2: After the heat preservation in Stage 1 is completed, adjust the atmosphere flow rate to 50 L / min, continue heating at a rate of 0.5 °C / min, and hold for 30 min every 50 °C increase in temperature;

[0089] Stage 3: When the temperature in Stage 2 rises to 350 °C, adjust the atmosphere flow rate to 80 L / min, continue heating at a rate of 0.5 °C / min, and hold for 60 min every 50 °C increase in temperature;

[0090] Stage 4: When the temperature in Stage 3 rises to 550 °C, adjust the atmosphere flow rate to 100 L / min, and cool down at a rate of 2 °C / min;

[0091] Stage 5: Wait until the temperature in Stage 4 drops to 400°C, adjust the atmosphere flow rate to 300 L / min, keep the temperature for 2 h, and then cool it down to 25°C at a rate of 0.5°C / min.

[0092] Comparative Example 2: Comparative Example 2 is based on Example 1. The difference between Comparative Example 2 and Example 1 is that the heat treatment step of the aluminum foil in S2 is removed, and it specifically includes the following steps:

[0093] Step 1: Take 10 pieces of silicon nitride ceramic green bodies and stack them inside the debinding fixture, and spray boron nitride separation powder between each green body to separate them;

[0094] Step 2: Cut the aluminum foil to obtain a thickness of 20 μm, a length of 1100 mm, and a width of 65 mm for backup;

[0095] Step 3: Take the aluminum foil cut in Step 2 and perform an edge wrapping treatment on the whole debinding fixture and the electronic ceramic green body in Step 1. The aluminum foil wraps the side edges, and the proportion of the upper and lower bottom areas wrapped by the aluminum foil is 1 / 4;

[0096] Step 4: Load the whole debinding fixture and green body with the edge wrapping completed in Step 3 into the debinding furnace for atmosphere debinding;

[0097] Step 5: After the atmosphere debinding is completed, remove the edge wrapping to obtain the debound sheet.

[0098] Among them, the atmosphere debinding includes the following 5 debinding stages:

[0099] Stage 1: Introduce an air atmosphere into the debinding furnace. According to the volume of each 500 L of the furnace body, set the atmosphere flow rate to 800 L / min, and heat it up to 200°C at a rate of 0.4°C / min, and keep the temperature for 100 min;

[0100] Stage 2: After the heat preservation in Stage 1 is completed, adjust the atmosphere flow rate to 50 L / min, continue to heat it up at a rate of 0.5°C / min, and keep the temperature for 30 min every time it is heated up by 50°C;

[0101] Stage 3: When the temperature in Stage 2 rises to 350°C, adjust the atmosphere flow rate to 80 L / min, continue to heat it up at a rate of 0.5°C / min, and keep the temperature for 60 min every time it is heated up by 50°C;

[0102] Stage 4: When the temperature in Stage 3 rises to 550°C, adjust the atmosphere flow rate to 100 L / min, and cool it down at a rate of 2°C / min;

[0103] Stage 5: Wait until the temperature in Stage 4 drops to 400°C, adjust the atmosphere flow rate to 300 L / min, keep the temperature for 2 h, and then cool it down to 25°C at a rate of 0.5°C / min.

[0104] Comparative Example 3: Comparative Example 3 is based on Example 1. The difference between Comparative Example 3 and Example 1 is that aluminum foil with a thickness of 40 μm is used, and the specific steps are as follows:

[0105] Step 1: Take 10 silicon nitride ceramic green bodies and stack them inside a debinding fixture. Spray boron nitride separation powder between each green body to separate them.

[0106] Step 2: Cut the aluminum foil to obtain a thickness of 40 μm, a length of 1100 mm, and a width of 65 mm. Place it in a muffle furnace and heat-treat it at 300 °C for 3 hours for standby.

[0107] Step 3: Take the heat-treated aluminum foil in Step 2 and perform an edge wrapping treatment on the entire debinding fixture and the electronic ceramic green body. The aluminum foil wraps the sides, and the proportion of the aluminum foil covering the upper and lower bottom areas is 1 / 4.

[0108] Step 4: Load the entire debinding fixture and the green body with the edge wrapping completed in Step 3 into a debinding furnace for atmosphere debinding.

[0109] Step 5: After the atmosphere debinding is completed, remove the edge wrapping to obtain a debound sheet.

[0110] Among them, the atmosphere debinding includes the following 5 debinding stages:

[0111] Stage 1: Introduce an air atmosphere into the debinding furnace. According to every 500 L of the furnace volume, set the atmosphere flow rate to 800 L / min, and heat up to 200 °C at a rate of 0.4 °C / min, and keep it warm for 100 min.

[0112] Stage 2: After the insulation in Stage 1 is completed, adjust the atmosphere flow rate to 50 L / min, continue to heat up at a rate of 0.5 °C / min, and keep it warm for 30 min every time the temperature rises by 50 °C.

[0113] Stage 3: When the temperature in Stage 2 rises to 350 °C, adjust the atmosphere flow rate to 80 L / min, continue to heat up at a rate of 0.5 °C / min, and keep it warm for 60 min every time the temperature rises by 50 °C.

[0114] Stage 4: When the temperature in Stage 3 rises to 550 °C, adjust the atmosphere flow rate to 100 L / min and cool down at a rate of 2 °C / min.

[0115] Stage 5: When the temperature in Stage 4 drops to 400 °C, adjust the atmosphere flow rate to 300 L / min, keep it warm for 2 h, and then cool down to 25 °C at a rate of 0.5 °C / min.

[0116] Comparative Example 4: Comparative Example 4 is based on Example 1. The difference between Comparative Example 4 and Example 1 is that the proportion of the aluminum foil covering the upper and lower bottom areas is 1 / 2; the specific steps are as follows:

[0117] Step 1: Take 10 green silicon nitride ceramic blanks and stack them inside a debinding fixture. Spray boron nitride powder for separating between each blank.

[0118] Step 2: Cut aluminum foil to obtain a thickness of 20 μm, a length of 1100 mm, and a width of 65 mm. Place it in a muffle furnace and heat-treat it at 300 °C for 3 hours for standby.

[0119] Step 3: Take the heat-treated aluminum foil from Step 2 and perform an edge wrapping treatment on the entire debinding fixture and the electronic ceramic green blanks in Step 1. The aluminum foil wraps the sides, and the proportion of the upper and lower bottom areas wrapped by the aluminum foil is 1 / 2.

[0120] Step 4: Load the entire debinding fixture and green blanks with the edge wrapping completed in Step 3 into a debinding furnace for atmosphere debinding.

[0121] Step 5: After the atmosphere debinding is completed, remove the edge wrapping to obtain a debound sheet.

[0122] Among them, the atmosphere debinding includes the following 5 debinding stages:

[0123] Stage 1: Introduce an air atmosphere into the debinding furnace. According to every 500 L of furnace volume, set the atmosphere flow rate to 800 L / min, and heat up to 200 °C at a rate of 0.4 °C / min, then hold for 100 min.

[0124] Stage 2: After the holding in Stage 1 is completed, adjust the atmosphere flow rate to 50 L / min and continue to heat up at a rate of 0.5 °C / min. Hold for 30 min every time the temperature rises by 50 °C.

[0125] Stage 3: When the temperature in Stage 2 rises to 350 °C, adjust the atmosphere flow rate to 80 L / min and continue to heat up at a rate of 0.5 °C / min. Hold for 60 min every time the temperature rises by 50 °C.

[0126] Stage 4: When the temperature in Stage 3 rises to 550 °C, adjust the atmosphere flow rate to 100 L / min and cool down at a rate of 2 °C / min.

[0127] Stage 5: When the temperature in Stage 4 drops to 400 °C, adjust the atmosphere flow rate to 300 L / min. After holding for 2 h, cool down to 25 °C at a rate of 0.5 °C / min.

[0128] Detection test

[0129] Take the debound sheets after edge wrapping and debinding in Examples 1 - 4 and Comparative Examples 1 - 4. The size of the debound sheet is 258 * 188 * 0.45. Use a warpage tester to perform warpage tests on the debound sheets. Uniformly measure the heights of 18 points on the entire debound sheet. Subtract the minimum height from the maximum height to obtain the height difference. Divide the height difference by the length of the debound sheet. The test results are as follows:

[0130] Maximum height / mm Minimum height / mm Height difference / mm Warpage‰ Example 1 0.784 0.452 0.332 1.29 Example 2 0.760 0.446 0.314 1.22 Example 3 0.791 0.466 0.325 1.26 Example 4 0.785 0.457 0.328 1.27 Comparative example 1 2.068 0.446 1.622 6.29 Comparative example 2 1.864 0.438 1.426 5.53 Comparative example 3 1.291 0.461 0.830 3.22 Comparative example 4 2.133 0.435 1.698 6.58

[0131] Conclusion: The present invention provides a method for edge wrapping and debinding of green bodies of electronic ceramics. By using aluminum foil to perform edge wrapping treatment on the green bodies and debinding fixtures according to this method and then placing them in a debinding furnace for debinding, an electronic ceramic debinding sheet with a lower warpage degree can be obtained.

[0132] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

Claims

1. A method for edge trimming and debinding of a green body of electronic ceramics, characterized in that, It includes the following steps: Step 1: Place the green body of electronic ceramics inside the debinding fixture in a stacked manner; Step 2: Cut the aluminum foil and conduct heat treatment for later use; Step 3: Take the aluminum foil after heat treatment in Step 2 and perform edge wrapping on the entire debinding fixture and the green body of electronic ceramics in Step 1; Step 4: Place the debinding fixture and the green body after edge wrapping in Step 3 as a whole into the debinding furnace for atmosphere debinding; Step 5: After the atmosphere debinding is completed, remove the edge wrapping to obtain the debound sheet; The edge wrapping treatment in Step 3 specifically is: the aluminum foil wraps the side edges, and the proportion of the upper and lower bottom areas wrapped by the aluminum foil is 1 / 4 - 1 / 3.

2. The edge - wrapping and debinding method of a green body of electronic ceramics according to claim 1, characterized in that, In Step 1, 8 - 15 green bodies of electronic ceramics are stacked inside the debinding fixture, and each green body is separated by spraying boron nitride powder for separating during sintering.

3. A method for edge trimming and debinding of a green body of electronic ceramics according to claim 1, characterized in that, The green body of electronic ceramics in Step 1 is one of the green bodies of silicon nitride, aluminum nitride, alumina, silicon carbide, and silicon powder ceramics.

4. A method for edge trimming and debinding of a green body of electronic ceramics according to claim 1, characterized in that, In Step 2, the thickness of the aluminum foil is 15 - 30 μm, the length is 900 - 1100 mm, and the width is 55 - 65 mm.

5. A method for edge trimming and debinding of a green body of electronic ceramics according to claim 1, characterized in that, The heat treatment in Step 2 is carried out at 300 °C for 1 - 3 h.

6. The edge wrapping and debinding method of a green body of electronic ceramics according to claim 1, characterized in that, The atmosphere debinding in Step 4 includes the following 5 debinding stages: Stage 1: Introduce air or nitrogen atmosphere into the debinding furnace, set the atmosphere flow rate to 200 - 800 L / min, and heat up to 200 - 240 °C at a rate of 0.4 °C / min, and keep it warm for 50 - 100 min; Stage 2: After the insulation in Stage 1 ends, adjust the atmosphere flow rate to 20 - 100 L / min, continue to heat up at a rate of 0.4 - 0.6 °C / min, and keep it warm for 20 - 30 min every time it heats up 50 - 60 °C; Stage 3: When the temperature in Stage 2 rises to 350 - 370 °C, adjust the atmosphere flow rate to 20 - 100 L / min, continue to heat up at a rate of 0.4 - 0.6 °C / min, and keep it warm for 60 - 80 min every time it heats up 50 - 60 °C; Stage 4: When the temperature in Stage 3 rises to 500 - 550 °C, adjust the atmosphere flow rate to 20 - 100 L / min, and cool down at a rate of 0.6 - 2 °C / min; Stage 5: When the temperature in Stage 4 drops to 400 - 450 °C, adjust the atmosphere flow rate to 60 - 300 L / min, keep it warm for 2 - 5 h, and then cool down to 20 - 25 °C at a rate of 0.5 - 5 °C / min.

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