A preparation method of an aluminum oxide copper clad plate reducing DCB ceramic black spots
By combining direct copper sintering with fluoride aqueous solution immersion with laser marking equipment, the problem of black spot defects in DBC ceramic substrates was solved, achieving high-yield and low-cost production of alumina copper clad substrates.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 四川富乐华半导体科技有限公司
- Filing Date
- 2026-03-25
- Publication Date
- 2026-06-23
AI Technical Summary
Black spot defects generated during the sintering process of DBC ceramic substrates lead to poor product appearance, reduced flatness, and high costs. These defects are difficult to avoid through simple processes, affecting product yield and cost.
A direct copper cladding sintering method combined with fluoride aqueous solution immersion and laser marking equipment is used to remove black spot residues on the semi-finished alumina copper clad substrate. The solubility is improved by combining HF and NH4F aqueous solutions, and the black spots are automatically identified and removed by laser marking equipment.
Significantly reduce the proportion of black spots to below 1%, maintain flexural strength without reduction, improve product yield and reduce manufacturing costs.
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Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention relates to the field of advanced ceramics preparation, and in particular to a method for preparing an alumina copper-clad substrate that reduces DCB ceramic black spots. Background Technology
[0002] Direct Bonded Copper Ceramic Substrate (DBC) is a process that uses an oxygen-containing eutectic solution of copper to directly bond copper foil onto ceramic, thereby achieving a bond between the ceramic and the copper sheet.
[0003] In the DBC sintering process, the nickel-chromium mesh belt in the tunnel furnace generates mesh belt ash containing NiO and Cr2O3 at high temperatures. During the ceramic substrate process, the mesh belt ash in the tunnel furnace settles onto the ceramic substrate with the furnace gas and forms 0.5mm~2mm black spot defects after sintering at 850-1080℃. Black spot defects have become a pain point in the industry.
[0004] On the one hand, customers (such as new energy vehicles and photovoltaic inverters) have strict requirements for the appearance of DBC substrates, and the aforementioned black spots directly lead to product scrapping; on the other hand, as heterogeneous particles, black spots may also reduce the flatness of the substrate, affecting subsequent processes, and are prone to cracking due to differences in thermal expansion coefficients during hot and cold cycles.
[0005] Due to the high cost of raw materials and sintering for DBC substrates, defects lead to low yield and high cost; moreover, the random generation and migration of mesh belt ash is difficult to avoid through simple processes, becoming a key bottleneck for process stability. Summary of the Invention
[0006] To address the aforementioned deficiencies, this invention provides a method for preparing an alumina copper-clad substrate with reduced DCB ceramic black spots. The black spot ratio is less than 1%, and the decrease in bending strength is 0%, which greatly improves product yield and reduces overall manufacturing costs.
[0007] The technical solution is: a method for preparing an alumina copper-clad substrate with reduced DCB ceramic black spots. The method obtains the alumina copper-clad substrate through direct copper sintering and black spot removal.
[0008] Furthermore, the method includes the following steps: S1, the alumina ceramic sheet and copper sheet are cleaned, dried, and the alumina is directly bonded to the copper and sintered to form a sintered substrate; S2, the sintered substrate is patterned and etched to form an alumina copper-clad substrate semi-finished product; S3, remove black spots from the semi-finished aluminum oxide copper-clad substrate; S4, cut to obtain an alumina copper-clad substrate.
[0009] Furthermore, S3 includes the following steps: S31, Immerse the semi-finished aluminum oxide copper-clad substrate in a fluoride aqueous solution; S32, the soaked aluminum oxide copper-clad substrate semi-finished product is cleaned and then baked; S33. The dried copper-clad aluminum oxide substrate semi-finished product is placed in a laser marking equipment for optical inspection. The laser marking equipment automatically identifies the position of the black dots and automatically marks and removes the black dot residue.
[0010] Furthermore, in S31, the aqueous fluoride solution is an aqueous solution of HF and / or NH4F.
[0011] Furthermore, in S31, the composition of the fluoride aqueous solution is: HF 10wt%~30wt%, NH4F 5wt%~15wt%, and the balance is pure water.
[0012] Furthermore, in S31, the soaking time is 3 to 8 minutes.
[0013] Furthermore, for S32, the baking temperature is 100℃~120℃, and the time is 5min~10min.
[0014] Furthermore, in S32, the cleaning is performed using pure water.
[0015] Furthermore, in S1, the alumina ceramic sheet is 132mm × 184mm, and the copper sheet is 132mm × 184mm.
[0016] Furthermore, the proportion of black spots on the alumina copper-clad substrate is less than 1%, and the decrease in bending strength is 0%.
[0017] Beneficial effects of the invention: This invention improves product yield and reduces overall manufacturing costs by immersing the semi-finished alumina copper-clad substrate produced by direct copper sintering in an immersion solution and using laser marking equipment to mark and remove black spot residues. This results in a black spot ratio of less than 1% and a bending strength reduction of 0% in the finished alumina copper-clad substrate. Detailed Implementation
[0018] The technical solution of the present invention will be described in detail below with specific embodiments. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention and not for limiting the claims of the present invention.
[0019] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "longitudinal," "lateral," "horizontal," "inner," "outer," "front," "rear," "top," and "bottom," etc., indicate the orientation or positional relationship based on the shown orientation or positional relationship, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0020] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "open," "installed," "connected," and "communicate" should be interpreted broadly. For example, they can refer to fixed connection, detachable connection, or integral connection; they can refer to direct connection or indirect connection through an intermediate medium; and they can refer to the connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0021] Unless otherwise specified, all inventions are existing technologies.
[0022] Unless otherwise specified, all materials involved in this invention are purchased from the market.
[0023] Example 1 A method for preparing a copper-clad alumina substrate semi-finished product includes the following steps: S1, clean and dry the alumina ceramic sheet and copper sheet, and sinter the alumina directly bonded to the copper to form a sintered substrate. The alumina ceramic sheet is 132mm×184mm and the copper sheet is 132mm×184mm.
[0024] S2, the sintered substrate is patterned and etched to form an alumina copper-clad substrate semi-finished product.
[0025] Example 2 The alumina copper-clad substrate semi-finished product prepared in Example 1 was used as raw material for this example.
[0026] A method for preparing an alumina copper-clad substrate further includes the following steps: S3, removing black spots from the copper-clad aluminum oxide substrate semi-finished product, including the following steps: S31, Immerse the copper-clad aluminum oxide substrate semi-finished product in an aqueous solution for 5.5 minutes.
[0027] The aqueous solution consists of 20wt% HF, 10wt% NH4F, and the remainder is pure water.
[0028] S32, the soaked aluminum oxide copper-clad substrate semi-finished product is cleaned with pure water and then baked at 110℃ for 8 minutes.
[0029] S33. The dried copper-clad aluminum oxide substrate semi-finished product is placed in a laser marking equipment for optical inspection. The laser marking equipment automatically identifies the position of the black dots and automatically marks and removes the black dot residue.
[0030] S4. Cut the semi-finished alumina copper-clad substrate from S33 to obtain the finished product, which is the first alumina copper-clad substrate.
[0031] Example 3 The alumina copper-clad substrate semi-finished product prepared in Example 1 was used as raw material for this example.
[0032] The difference compared to Example 2 is as follows: In S31, the aqueous solution consists of: HF 10wt%, NH4F 5wt%, and the remainder is pure water.
[0033] Alumina copper-clad substrate 2 was obtained.
[0034] Example 4 The alumina copper-clad substrate semi-finished product prepared in Example 1 was used as raw material for this example.
[0035] The difference compared to Example 2 is as follows: In S31, the aqueous solution consists of: HF 30wt%, NH4F 15wt%, and the remainder is pure water.
[0036] Obtain alumina copper-clad substrate 3.
[0037] Example 5 The alumina copper-clad substrate semi-finished product prepared in Example 1 was used as raw material for this example.
[0038] The difference compared to Example 3 is as follows: In S31, the soaking time is 3 minutes.
[0039] Four aluminum oxide copper-clad substrates were obtained.
[0040] Example 6 The alumina copper-clad substrate semi-finished product prepared in Example 1 was used as raw material for this example.
[0041] The difference compared to Example 4 is as follows: In S31, the soaking time is 8 minutes.
[0042] Five copper-clad aluminum oxide substrates were obtained.
[0043] Example 7 The alumina copper-clad substrate semi-finished product prepared in Example 1 was used as raw material for this example.
[0044] The difference compared to Example 2 is as follows: The aqueous solution consists of: HF 5wt%, NH4F 10wt%, and the remainder is pure water.
[0045] Obtain a copper-clad aluminum oxide substrate.
[0046] Example 8 The alumina copper-clad substrate semi-finished product prepared in Example 1 was used as raw material for this example.
[0047] The difference compared to Example 2 is as follows: The aqueous solution consists of: HF 35wt%, NH4F 10wt%, and the remainder is pure water.
[0048] Seven aluminum oxide copper-clad substrates were obtained.
[0049] Example 9 The alumina copper-clad substrate semi-finished product prepared in Example 1 was used as raw material for this example.
[0050] The difference compared to Example 2 is as follows: The aqueous solution consists of: HF 20wt%, NH4F 1wt%, and the remainder is pure water.
[0051] Eight, copper-clad aluminum oxide substrates were obtained.
[0052] Example 10 The alumina copper-clad substrate semi-finished product prepared in Example 1 was used as raw material for this example.
[0053] The difference compared to Example 2 is as follows: The aqueous solution consists of 20wt% HF, 20wt% NH4F, and the remainder is pure water.
[0054] Nine aluminum oxide copper-clad substrates were obtained.
[0055] Example 11 The alumina copper-clad substrate semi-finished product prepared in Example 1 was used as raw material for this example.
[0056] The difference compared to Example 2 is as follows: The aqueous solution consists of 20 wt% HF and the remainder is pure water.
[0057] Ten aluminum oxide copper-clad substrates were obtained.
[0058] Example 12 The alumina copper-clad substrate semi-finished product prepared in Example 1 was used as raw material for this example.
[0059] The difference compared to Example 2 is as follows: The aqueous solution consists of 20wt% NH4F and the remainder is pure water.
[0060] Eleven aluminum oxide copper-clad substrates were obtained.
[0061] Comparative Example 1 The alumina copper-clad substrate semi-finished product prepared in Example 1 was used as raw material for this comparative example.
[0062] The difference compared to Example 2 is as follows: In this comparative example, step S3 is omitted. The alumina copper-clad substrate semi-finished product prepared in Example 1 is directly cut in step S4 to obtain alumina copper-clad substrate twelve.
[0063] The proportion of black spots and the decrease in the bending strength of the ceramic tiles were detected on aluminum oxide copper clad substrate 1 and aluminum oxide copper clad substrate 21. The results are shown in Table 1.
[0064] Table 1
[0065] As shown in Table 1, compared with Comparative Example 1, the proportion of black spots on the copper-clad aluminum oxide substrate semi-finished product decreased sharply from 8% in Comparative Example 1 through Example 12. This was due to the effective combination of NH4F and HF, with NH4F providing additional F⁻, promoting the formation of the fluorine-aluminum complex ([AlF6)). 3- It exists stably, significantly increasing the solubility of Al2O3, and NH4 + Without introducing impurities, the reaction rate is 2 to 3 times faster than that of pure HF solution. When HF is 10wt% to 30wt% and NH4F is 5wt% to 15wt%, the proportion of black spots is reduced to 0.05% while keeping the decrease in the bending strength of the ceramic tile at 0%.
[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing an alumina copper-clad substrate with reduced DCB ceramic black spots, characterized in that, This method obtains copper-clad aluminum oxide substrates through direct copper sintering and black spot removal.
2. The method for preparing an alumina copper-clad substrate with reduced DCB ceramic black spots according to claim 1, characterized in that, The method includes the following steps: S1, the alumina ceramic sheet and copper sheet are cleaned, dried, and the alumina is directly bonded to the copper and sintered to form a sintered substrate; S2, the sintered substrate is patterned and etched to form an alumina copper-clad substrate semi-finished product; S3, remove black spots from the semi-finished aluminum oxide copper-clad substrate; S4, cut to obtain an alumina copper-clad substrate.
3. The method for preparing an alumina copper-clad substrate with reduced DCB ceramic black spots according to claim 2, characterized in that, S3 includes the following steps: S31, Immerse the semi-finished aluminum oxide copper-clad substrate in a fluoride aqueous solution; S32, the soaked aluminum oxide copper-clad substrate semi-finished product is cleaned and then baked; S33. The dried copper-clad aluminum oxide substrate semi-finished product is placed in a laser marking equipment for optical inspection. The laser marking equipment automatically identifies the position of the black dots and automatically marks and removes the black dot residue.
4. The method for preparing an alumina copper-clad substrate with reduced DCB ceramic black spots according to claim 3, characterized in that, In S31, the aqueous solution of fluoride is HF or / and NH4F aqueous solution.
5. The method for preparing an alumina copper-clad substrate with reduced DCB ceramic black spots according to claim 4, characterized in that, In S31, the composition of the fluoride aqueous solution is: HF 10wt%~30wt%, NH4F 5wt%~15wt%, and the balance is pure water.
6. The method for preparing an alumina copper-clad substrate with reduced DCB ceramic black spots according to claim 3, characterized in that, In S31, the soaking time is 3 to 8 minutes.
7. The method for preparing an alumina copper-clad substrate with reduced DCB ceramic black spots according to claim 3, characterized in that, S32, baking temperature is 100℃~120℃, time is 5min~10min.
8. The method for preparing an alumina copper-clad substrate with reduced DCB ceramic black spots according to claim 3, characterized in that, In S32, the cleaning is done with pure water.
9. The method for preparing an alumina copper-clad substrate with reduced DCB ceramic black spots according to claim 2, characterized in that, In S1, the alumina ceramic sheet is 132mm×184mm and the copper sheet is 132mm×184mm.
10. The method for preparing an alumina copper-clad substrate with reduced DCB ceramic black spots according to any one of claims 1-9, characterized in that, The proportion of black spots on the copper-clad alumina substrate is less than 1%, and the decrease in bending strength is 0%.