Preparation method of AMB copper-clad ceramic product containing sinking groove
By combining vacuum brazing and dry film exposure and development, the depth and roughness of the sinker in AMB copper-clad ceramic products are controlled, solving the inconsistency problem caused by the etching process and achieving a high-efficiency and low-cost preparation process.
Patent Information
- Application Number
- CN202511701676.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-19
- Publication Date
- 2026-02-13
AI Technical Summary
In the current manufacturing process of AMB copper-clad ceramic products, the etching process leads to inconsistent depth of the sinking groove and difficulty in controlling the roughness, resulting in problems such as low yield, high cost and poor precision.
A combination of vacuum brazing and dry film exposure development was used to control the depth of the sink to H±0.02mm by stacking an oxygen-free copper and brazing layer. Excess layers were removed by a single copper etching and solder etching process to avoid inconsistencies in the etching process.
It achieves precise control over the depth and roughness of the sinking groove, avoids inconsistencies caused by the etching process, simplifies the preparation process, improves yield, and saves raw material and labor costs.
Smart Images
Figure CN121531583A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of brazing, in particular to a preparation method of AMB copper-clad ceramic product containing sinking groove. BACKGROUND
[0002] AMB copper-clad ceramic circuit board mainly involves three raw materials in the preparation process, which are ceramic substrate, copper and brazing material. The ceramic is mainly silicon nitride, aluminum nitride and aluminum oxide, with thermal conductivity of 21-170 W / (m·K), and the thickness of the ceramic is ≤2 mm. The brazing material is mainly silver-copper-titanium or copper-titanium composition solder paste or preformed solder sheet, and the thickness of the printed thick film or preformed solder sheet is generally ≤0.05 mm. The copper is mainly oxygen-free copper with purity of more than 99.99%, and the thermal conductivity is about 390 W / (m·K), and the thickness of the copper strip is ≤2 mm.
[0003] AMB copper-clad ceramic substrate is widely used in semiconductor module device packaging with high power, high heat dissipation and high reliability requirements due to its low porosity, high thermal conductivity and high peel strength. In recent years, with the requirements of high power density and low ESL (equivalent series inductance) of power modules, AMB backing plate and chip are embedded in PCB products. Accordingly, the copper surface of AMB product starts to have sinking grooves as shown in Figure 1 .
[0004] According to the existing AMB product manufacturing process, the product needs to go through AMB mother plate brazing sintering, sinking groove etching, line distance etching and other processes in sequence. Dry film, exposure, development, etching and film removal are repeated in the two etching processes. The yield is reduced due to the damage of dry film and other reasons in the two etching processes, which is not conducive to batch production. Moreover, the sinking groove area places the chip, and the roughness Ra and flatness of the sinking groove area are extremely fine, which is difficult to meet the requirements by conventional chemical etching. In summary, the process is complex, the cost is high, the precision is poor and the yield is low. SUMMARY
[0005] The purpose of the present application is to overcome the defects of the prior art and provide a preparation method of AMB copper-clad ceramic product containing sinking groove. The depth of the sinking groove originally controlled by etching process is changed into the thickness of the combined brazing layer three + oxygen-free copper three, so that the depth of the sinking groove can be controlled within H±0.02 mm, and the problems of etching chamfer of the sinking groove itself and inconsistent etching depth between the sinking grooves caused by etching process are avoided.
[0006] The purpose of the present application is achieved as follows: a preparation method of AMB copper-clad ceramic product containing sinking groove, comprising the following steps: 1) Lamination: from top to bottom, the structure of oxygen-free copper three, brazing layer three, oxygen-free copper two, brazing layer two, ceramic layer, brazing layer one and oxygen-free copper one is laminated, and the brazing layer three is provided with an opening in the line distance groove area; 2) AMB template vacuum brazing: sintering by vacuum brazing to form AMB mother plate; 3) Groove etching: dry film exposure and development is used to realize pattern transfer, and the etching is performed on the oxygen-free copper three of the sink groove area, and the copper etching is performed on the oxygen-free copper two and oxygen-free copper three of the line distance groove area. 4) Brazing layer etching: removing the brazing layer three on the surface of the sink groove and the brazing layer two in the line distance groove.
[0007] Further, the depth H of the sink groove is H±0.02mm, the bottom surface roughness of the sink groove is Rz≤16um, and the flatness is 0.05mm.
[0008] Further, step 2) specifically includes: sintering by vacuum brazing, the sintering vacuum degree is ≤10E-4Pa, the vacuum brazing peak temperature is 850℃-950℃, and the holding time is 10min-50min.
[0009] Further, the step 3) includes: realizing pattern transfer by dry film exposure and development, wherein the dry film thickness is 30-75um, the CuCl2 system copper etching solution is used for copper etching of the oxygen-free copper two and oxygen-free copper three of the groove area, the copper ion concentration is 90-180g / L, the hydrochloric acid concentration is 2.0±0.5N, the solution temperature is 50±5℃, and the spray pressure is 1.0-2.0kg / cm 3 .
[0010] Further, the step 4) specifically includes: etching the exposed brazing layer three and brazing layer two after copper etching by using solder etching solution, wherein the solder etching solution PH is ≥8, the solder etching time is 60±15min, and the solder etching solution temperature is ≤35℃.
[0011] The above technology is adopted in the present application, compared with the prior art, the beneficial effects are: 1) the depth of the sink groove originally needing to be controlled by etching process is changed into the thickness of the brazing layer three+oxygen-free copper three of the combination, the depth of the sink groove can be controlled in H±0.02mm, and the problems of etching chamfer of the sink groove itself and inconsistent etching depth between the sink grooves caused by etching process are avoided.
[0012] 2) Since the brazing layer three is used as a mask material, there is no problem of inconsistent etching parameters caused by the inconsistent depth of the line distance groove and the sink groove in the copper etching process, and the bottom of the sink groove and the oxygen-free copper two will not be attacked by the copper etching solution, after the brazing layer three etching, the bottom of the sink groove satisfies the surface roughness Rz≤16um and the flatness 0.05mm, and it is ensured that the chip will not be abnormally broken in the embedded packaging process.
[0013] 3) only need once copper etching and solder etching process, solve the size interference in the process of two etching yield loss problem, realize simple preparation, and save raw materials and labor cost in the process. BRIEF DESCRIPTION OF DRAWINGS
[0014] Figure 1 Prior art containing sink groove AMB product schematic diagram.
[0015] Figure 2 Flow chart of the present application.
[0016] Figure 3 AMB product containing sink groove of the present application schematic diagram.
[0017] Figure 4 Embodiment schematic diagram of the present application.
[0018] Among them, 101 is oxygen-free copper one, 102 is oxygen-free copper two, 103 is oxygen-free copper three, 201 is solder layer one, 202 is solder layer two, 203 is solder layer three, 301 is ceramic layer, 401 is sink groove, and 402 is line distance groove. DETAILED DESCRIPTION
[0019] As Figures 2-4 indicated, a preparation method of an AMB copper-clad ceramic product containing a sink groove, comprising the following steps: 1) laminating: from top to bottom, according to the structure of oxygen-free copper three 103, solder layer three 203, oxygen-free copper two 102, solder layer two 202, ceramic layer 301, solder layer one 201 and oxygen-free copper one 101, the solder layer three 203 is reserved with an opening in the line distance groove area; a pre-patterned solder layer is selected, which is composed of Cu-Sn-Ti, and the solder layer pre-patterning can be realized by a conventional steel knife mold, wherein the cutting depth is h±0.01 mm, the tool material is DC53 mold steel, and the cutting mouth flatness is Ra≤1.5.
[0020] 2) AMB template vacuum brazing: sintering by vacuum brazing to form an AMB master plate; sintering by vacuum brazing, sintering vacuum degree ≤10E-4Pa, vacuum brazing peak temperature 850-950℃, holding time 10-50min; 3) groove etching: realizing pattern transfer by dry film exposure and development, etching oxygen-free copper three in the sink groove area, and copper etching oxygen-free copper three and oxygen-free copper two in the line distance groove area; realizing pattern transfer by dry film exposure and development, wherein the dry film thickness is 30-75um, CuCl2 system copper etching solution is used for copper etching oxygen-free copper two and oxygen-free copper three in the groove area, the copper ion concentration is 90-180g / L, the hydrochloric acid concentration is 2.0±0.5N, the solution temperature is 50±5℃, and the spray pressure is 1.0-2.0kg / cm3 .
[0021] 4) solder layer etching: removing the solder layer three on the surface of the sink groove and the solder layer two in the line distance groove; after the copper etching is completed, the solder layer three and the solder layer two exposed are etched by solder etching solution, wherein the PH of the solder etching solution is greater than or equal to 8, the solder etching time is 60±15 min, the temperature of the solder etching solution is less than or equal to 35℃; the depth H of the sink groove is H±0.02 mm, the roughness of the bottom surface of the sink groove is Rz≤16um, and the flatness is 0.05 mm.
[0022] The present application provides a preparation method of an AMB copper-clad ceramic product containing a sink groove, which changes the depth of the sink groove originally controlled by an etching process into the thickness of the combined solder layer three + oxygen-free copper three, so that the depth of the sink groove can be controlled to H±0.02 mm, avoiding the problems of etching chamfer of the sink groove itself and inconsistent etching depth between the sink grooves caused by the etching process; it can be realized by only one copper etching and solder etching process, solving the yield loss problem caused by size interference in the twice etching process of the existing process, realizing simple preparation, and saving raw material and labor cost in the process.
[0023] The present application is not limited to the above embodiments, and based on the technical solutions disclosed in the present application, those skilled in the art can make some substitutions and modifications to some technical features without creative labor, and these substitutions and modifications are all within the protection scope of the present application.
Claims
1. A method for preparing an AMB copper-clad ceramic product with a sinking groove, characterized in that, Includes the following steps: 1) Stacking: The layers are stacked from top to bottom according to the structure of oxygen-free copper layer 3, brazing layer 3, oxygen-free copper layer 2, brazing layer 2, ceramic layer, brazing layer 1, and oxygen-free copper layer 1. The brazing layer 3 has an opening reserved in the line distance from the trench area. 2) Vacuum brazing of AMB template: AMB master board is formed by sintering using vacuum brazing. 3) Trench etching: The pattern transfer is achieved by dry film exposure and development. The oxygen-free copper 3 in the sinking trench area is etched, and the oxygen-free copper 3 and oxygen-free copper 2 in the line spacing trench area are etched. 4) Etching of brazing layer: Remove brazing layer three on the surface of the sinking groove and brazing layer two in the spacing groove.
2. The method for preparing an AMB copper-clad ceramic product with a sinking tank according to claim 1, characterized in that, The depth H of the sinking trough is H±0.02mm, and the surface roughness of the bottom of the sinking trough is Rz≤16um and the flatness is 0.05mm.
3. The method for preparing an AMB copper-clad ceramic product with a sinking groove according to claim 1, characterized in that, Step 2) specifically includes: sintering by vacuum brazing, with a sintering vacuum degree ≤10E-4Pa, a peak vacuum brazing temperature of 850℃-950℃, and a holding time of 10min-50min.
4. The method for preparing an AMB copper-clad ceramic product with a sinking tank according to claim 1, characterized in that, Step 3) includes: pattern transfer using dry film exposure and development, wherein the dry film thickness is 30-75 μm; copper etching of oxygen-free copper 2 and oxygen-free copper 3 in the trench area using a CuCl2 system copper etching solution, with a copper ion concentration of 90-180 g / L, a hydrochloric acid concentration of 2.0 ± 0.5 N, a solution temperature of 50 ± 5 °C, and a spray pressure of 1.0-2.0 kg / cm². 3 .
5. The method for preparing an AMB copper-clad ceramic product with a sinking tank according to claim 1, characterized in that, Step 4) specifically includes: using solder etching solution to etch the exposed brazing layer 3 and brazing layer 2 after copper etching, wherein the solder etching solution has a pH ≥ 8, the solder etching time is 60 ± 15 min, and the solder etching solution temperature is ≤ 35℃.