Precision AMB ceramic circuit board and preparation method therefor
By grinding, copper plating, and polishing the AMB ceramic copper-clad substrate, its surface morphology and density are improved, solving the problems of chip misalignment and weak bonding caused by the non-dense copper foil surface, and achieving better chip adhesion.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- JIANGSU FERROTEC SEMICON TECH CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-07-23
AI Technical Summary
In the vacuum brazing process, the copper foil surface of the AMB ceramic copper-clad substrate is not dense, which leads to problems such as easy displacement, weak bonding, and easy slippage of the chip during the chip attachment process.
The surface morphology and density of the AMB ceramic copper-clad substrate are improved by grinding, copper plating and polishing. Then, precision lines are etched and silver films and chips are attached.
This method improves the adhesion between the AMB ceramic copper-clad substrate and the chip, solving the problems of chip misalignment and weak bonding in traditional methods, and resulting in a smoother and denser copper foil surface.
Smart Images
Figure CN2025098607_23072026_PF_FP_ABST
Abstract
Description
A precision AMB ceramic circuit board and its fabrication method Technical Field
[0001] This invention relates to the field of ceramic substrate surface treatment technology, specifically a precision AMB ceramic circuit board and its preparation method. Background Technology
[0002] AMB (Active Metal Brazing Ceramic Substrate) is an advanced technology developed based on DBC (Digital Copper Clad) technology. At a high temperature of around 800℃, AgCu solder containing active elements Ti and Zr wets and reacts at the interface between the ceramic and metal, achieving heterogeneous bonding between the ceramic and metal. AMB ceramic copper-clad substrates achieve bonding through a chemical reaction between the ceramic and active metal solder paste at high temperatures, resulting in higher bonding strength and better reliability. This makes them ideal for connectors or applications requiring high current carrying capacity and heat dissipation.
[0003] AMB ceramic copper-clad substrates are a type of ceramic heat dissipation substrate used in industrial applications. However, during the vacuum brazing (high-temperature sintering) process between the ceramic substrate and the copper foil, various uncontrollable factors prevent the copper foil surface from achieving good density, resulting in the formation of fine "grains." In post-processing, the copper foil undergoes multiple processes of strong acid etching, especially since its surface needs to be etched with various patterns conforming to the relevant drawings. Therefore, over-etching by the chemical solutions is inevitable. In addition, some copper foils have relatively obvious grain boundaries after vacuum brazing, and chemical residues in these grain boundaries accelerate the over-etching phenomenon on the copper foil surface. Furthermore, other foreign matter can easily become trapped in the grain boundaries, making them difficult to clean in subsequent processes. As time goes on, the over-etching phenomenon becomes more pronounced, leading to abnormal problems such as chip misalignment, weak bonding, and easy slippage during the chip attachment process of the AMB ceramic copper-clad substrate, causing significant difficulties in chip attachment and connection.
[0004] Based on this, the present invention will study how to eliminate the grains that are naturally formed in the AMB ceramic copper-clad substrate during the vacuum brazing process, so as to obtain a smooth, denser and better flattened metal surface, in order to solve the difficult problems such as chip misalignment, weak bonding and easy slippage that occur in the later packaging process.
[0005] This invention utilizes innovative techniques such as "grinding," "electroplating," and "polishing" to alter the surface morphology, grain size, roughness, and flatness of traditional AMB ceramic copper-clad substrates, thereby improving the adhesion between the AMB ceramic copper-clad substrate and the chip, resulting in a more robust bonding performance. Summary of the Invention
[0006] The purpose of this invention is to provide a precision AMB ceramic circuit board and its preparation method to solve the problems raised in the prior art.
[0007] To achieve the above objectives, the present invention provides the following technical solution:
[0008] A precision AMB ceramic circuit board is prepared by first grinding, copper plating and polishing the AMB ceramic copper-clad substrate, then etching a precision circuit pattern on its surface, and finally attaching a silver film and a chip to the surface and heating and curing them respectively.
[0009] Furthermore, the method for fabricating the precision AMB ceramic circuit board includes the following steps:
[0010] S1: Grinding process of AMB ceramic copper-clad substrate;
[0011] S2: After S1, copper plating is performed on the AMB ceramic copper-clad substrate;
[0012] S3: After S2, the AMB ceramic copper-clad substrate is polished and brushed.
[0013] S4: After S3, a precision circuit pattern is etched on the surface of the AMB ceramic copper-clad substrate. Then, a silver film and a chip are attached to the surface in sequence and heated and cured to obtain a precision AMB ceramic circuit board.
[0014] Furthermore, the grinding process is carried out by mechanical grinding, specifically: the AMB ceramic copper-clad substrate is mechanically ground by ceramic brush 1 and ceramic brush 2 of a brushing machine; wherein, the parameters of mechanical grinding are: grinding speed of 0.8 to 1.0 m / min, current of ceramic brush 1 of 0.9 to 1.1 A, current of ceramic brush 2 of 0.3 to 0.4 A, and grinding thinning thickness of 15 to 35 μm.
[0015] Mechanical grinding reduces the thickness of the copper foil on the AMB ceramic copper-clad substrate, facilitating subsequent copper plating and improving the morphology and quality of the copper foil on the ceramic copper-clad substrate.
[0016] Furthermore, the ceramic brush needs to perform a brush mark test after grinding 1,500 AMB ceramic copper-clad substrates. If the brush marks are obviously uneven in thickness, the entire brush needs to be adjusted.
[0017] Furthermore, the copper plating is performed by electroplating. The specific process is as follows: the polished AMB ceramic copper-clad substrate is first degreased and activated in sequence, then placed in an electroplating solution for electroplating, and finally cleaned and dried with hot water at 50-60°C to complete the copper plating.
[0018] Furthermore, the specific degreasing process is as follows: the ground AMB ceramic copper-clad substrate is placed in an acidic degreasing agent and soaked at 50-60°C for 2-3 minutes. After being taken out, it is washed with hot water at 50-60°C and then rinsed twice with overflow water to complete the degreasing.
[0019] Furthermore, the specific activation process is as follows: the degreased AMB ceramic copper-clad substrate is placed in 2-4 wt% concentrated sulfuric acid and soaked for 1-2 minutes. After removal, it is rinsed twice with overflow water to complete the activation.
[0020] Furthermore, the electroplating solution comprises the following components at the following concentrations: copper sulfate 80–120 g / L, concentrated sulfuric acid 100–140 mL / L, chloride ions 60–100 ppm, additive I 5–15 mL / L, additive II 0.2–0.4 g / L, and deionized water as the solvent.
[0021] Further, the preparation method of additive I is as follows: (1) 5-bromo-2,2'-bipyridine is added to anhydrous ethanol and stirred to dissolve, so as to obtain an ethanol solution of 5-bromo-2,2'-bipyridine; (2) fatty alcohol ethoxy compound is added to water and stirred to dissolve, so as to obtain an aqueous solution of fatty alcohol ethoxy compound; (3) the ethanol solution of 5-bromo-2,2'-bipyridine and the aqueous solution of fatty alcohol ethoxy compound are thoroughly mixed to obtain additive I.
[0022] Further, the additive I comprises the following components at concentrations of 8-16 g / L 5-bromo-2,2'-bipyridine, 24-48 g / L fatty alcohol ethoxylate, and a 50 wt% ethanol solution.
[0023] Furthermore, the mass ratio of the 5-bromo-2,2'-bipyridine to the fatty alcohol ethoxy compound is 1:3.
[0024] Additive I is composed of a mixture of 5-bromo-2,2'-bipyridine and fatty alcohol ethoxy compounds. Among them, 5-bromo-2,2'-bipyridine can promote electroplating within a certain concentration and has a key influence on the morphology and performance of the electroplated layer. The fatty alcohol ethoxy compounds can act as nonionic surfactants, which can reduce the surface tension of the electroplating solution and improve the pore-filling ability of the electroplating solution, thereby making the coating crystallization more dense and stable.
[0025] Further, the preparation method of additive II is as follows: (1) 4'-(3-pyridyl)-2,2':6',2”-terpyridine is added to dichloromethane and stirred to dissolve, so as to obtain a dichloromethane solution of 4'-(3-pyridyl)-2,2':6',2”-terpyridine; (2) cerium nitrate is added to methanol and stirred to dissolve, and then the dichloromethane solution of 4'-(3-pyridyl)-2,2':6',2”-terpyridine is slowly added dropwise to it. After stirring and mixing for 1 to 2 hours, the filtrate is collected by filtration. After standing for 48 to 96 hours, the crystals are collected to obtain additive II.
[0026] Furthermore, the mass ratio of 4'-(3-pyridyl)-2,2':6',2”-terpyridine to cerium nitrate is 2:1.
[0027] Additive II is prepared by forming a complex of 4'-(3-pyridyl)-2,2':6',2”-terpyridine and cerium nitrate. Adding rare earth complexes to the electroplating solution can promote electroplating, thereby facilitating the formation of a dense and well-adhered coating. It can also work synergistically with Additive I to promote copper electroplating, so that the adhesion and surface quality of the copper foil can reach an ideal state.
[0028] Furthermore, the parameters for the electroplating process are: temperature of 40–50°C, and current density of 1–3 A / dm³. 2 The electroplating time is 2-3 hours, the cathode is copper, and the plating thickness is 25-50 μm.
[0029] Electroplating can compensate for the thickness of the copper foil that was previously ground away, and it can also produce copper foil with a more uniform and dense quality.
[0030] Furthermore, the polishing process specifically involves the following steps: after copper plating, the AMB ceramic copper-clad substrate is successively polished by non-woven brush 1 and non-woven brush 2 of a brushing machine; the polishing parameters are: the polishing speed is 1.0 to 1.2 m / min, the current of non-woven brush 1 is 1.0 to 1.2 A, and the current of non-woven brush 2 is 0.9 to 1.1 A.
[0031] After copper plating, polishing and brushing can remove defects such as unevenness and spots on the plating surface.
[0032] Furthermore, the non-woven fabric brush needs to be replaced and adjusted after polishing 3000 to 4000 AMB ceramic copper-clad substrates.
[0033] Compared with the prior art, the beneficial effects of the present invention are:
[0034] 1. The present invention changes the metallic morphology of the surface of the traditional AMB ceramic copper-clad substrate, specifically including: (1) eliminating the irregular and polycrystalline appearance of the copper foil surface; (2) obtaining a smoother and denser copper foil surface;
[0035] 2. This invention solves the difficult problems of misalignment, weak bonding, and easy slippage when attaching traditional AMB ceramic copper-clad substrates to chips;
[0036] 3. This invention improves the surface properties of the electroplated copper foil by adding additives I and II to the electroplating solution;
[0037] 4. The implementation of this invention can better meet market demands, has great application prospects, and is of great significance. Attached Figure Description
[0038] Figure 1 is a schematic diagram of the structure of the product of the present invention;
[0039] Figure 2 shows the metallographic image of the copper foil of the AMB ceramic copper-clad substrate before the three-step improvement treatment of grinding, copper plating and polishing.
[0040] Figure 3 shows the metallographic image of the copper foil of the AMB ceramic copper-clad substrate after three-step improvement treatment: grinding, copper plating, and polishing. Detailed Implementation
[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0042] It should be noted that the process parameters not specified in the following embodiments are all conventional conditions; all raw materials can be obtained from publicly available commercial sources; and all water used is deionized water.
[0043] In the following embodiments, an AMB ceramic copper-clad substrate with double-sided copper cladding was selected for improvement treatment. The theoretical thickness of a single layer of copper foil is 0.8 mm, the theoretical thickness of the ceramic substrate is 0.32 mm, and the theoretical total thickness of the AMB ceramic copper-clad substrate is 0.8 × 2 + 0.32 = 1.92 mm.
[0044] Preliminary preparations:
[0045] 1. Preparation of Additive I: (1) 12g of 5-bromo-2,2'-bipyridine was added to 300mL of anhydrous ethanol and stirred to dissolve, thus obtaining an ethanol solution of 5-bromo-2,2'-bipyridine; (2) 36g of fatty alcohol polyoxyethylene ether was added to 300mL of deionized water and stirred to dissolve, thus obtaining an aqueous solution of fatty alcohol polyoxyethylene ether; (3) The ethanol solution of 5-bromo-2,2'-bipyridine and the aqueous solution of fatty alcohol ethoxy compound were thoroughly mixed and 400mL of 50wt% ethanol solution was added and the volume was adjusted to 1L to obtain Additive I.
[0046] 2. Preparation of Additive II: (1) Add 4g of 4'-(3-pyridyl)-2,2':6',2”-terpyridine to 50mL of dichloromethane, stir and dissolve to obtain a dichloromethane solution of 4'-(3-pyridyl)-2,2':6',2”-terpyridine; (2) Add 2g of cerium nitrate to 50mL of methanol, stir and dissolve, then slowly add the dichloromethane solution of 4'-(3-pyridyl)-2,2':6',2”-terpyridine to it, stir and mix for 1.5h, filter and collect the filtrate, let it stand for 72h, collect the crystals and obtain Additive II.
[0047] Example 1: A method for fabricating a precision AMB ceramic circuit board:
[0048] In this embodiment, the actual average thickness of the AMB ceramic copper-clad substrate before improvement was 1.916 mm;
[0049] S1: Grinding process:
[0050] The AMB ceramic copper-clad substrate was mechanically polished by ceramic brush 1 and ceramic brush 2 of a brushing machine. The parameters of the mechanical polishing were as follows: polishing speed of 0.9m / min, current of ceramic brush 1 of 1A, current of ceramic brush 2 of 0.35A, polishing thickness reduction of 31μm, and average thickness of AMB ceramic copper-clad substrate after polishing of 1.885mm.
[0051] S2: Copper plating treatment:
[0052] (1) Place the ground AMB ceramic copper-clad substrate into TD-121 acidic degreasing agent, soak it at 55°C for 2.5 min, take it out, wash it with hot water at 55°C, and then wash it twice with overflow water to complete the degreasing.
[0053] (2) The degreased AMB ceramic copper-clad substrate was placed in 3wt% concentrated sulfuric acid and soaked for 1.5 min. It was then removed and rinsed twice with overflow water to complete the activation.
[0054] (3) The activated AMB ceramic copper-clad substrate is placed in the electroplating solution for electroplating treatment, and finally cleaned and dried with hot water at 55°C to complete the copper plating.
[0055] The electroplating solution contains the following components at the following concentrations: copper sulfate 100g / L, concentrated sulfuric acid 120mL / L, chloride ions 80ppm, additive I 10mL / L, additive II 0.3g / L, and the solvent is deionized water.
[0056] The electroplating parameters are: temperature 45℃, current density 2A / dm³. 2 The electroplating time was 2.5 hours, the cathode was a copper ball, and the plating thickness was 43 μm, meaning that the average thickness of the AMB ceramic copper-clad substrate after electroplating was 1.928 mm.
[0057] S3: Brush treatment:
[0058] After electroplating, the AMB ceramic copper-clad substrate is polished by nylon brush 1 and nylon brush 2 of a brushing machine. The polishing parameters are: polishing speed of 1.1m / min, current of nylon brush 1 of 1.1A and current of nylon brush 2 of 1A.
[0059] S4: After polishing, a precision circuit pattern is etched on the surface of the AMB ceramic copper-clad substrate. Then, a silver film and a chip are attached to the surface in sequence and heated and cured to obtain a precision AMB ceramic circuit board.
[0060] Example 2: A method for preparing a precision AMB ceramic circuit board:
[0061] In this embodiment, the actual average thickness of the AMB ceramic copper-clad substrate before improvement was 1.906 mm;
[0062] S1: Grinding process:
[0063] The AMB ceramic copper-clad substrate was mechanically polished by ceramic brush 1 and ceramic brush 2 of a brushing machine. The mechanical polishing parameters were as follows: polishing speed of 0.9 m / min, current of ceramic brush 1 of 1 A, current of ceramic brush 2 of 0.35 A, polishing thickness reduction of 19 μm, and average thickness of the AMB ceramic copper-clad substrate after polishing of 1.887 mm.
[0064] S2: Copper plating treatment:
[0065] (1) Place the ground AMB ceramic copper-clad substrate into TD-121 acidic degreasing agent, soak it at 55°C for 2.5 min, take it out, wash it with hot water at 55°C, and then wash it twice with overflow water to complete the degreasing.
[0066] (2) The degreased AMB ceramic copper-clad substrate was placed in 3wt% concentrated sulfuric acid and soaked for 1.5 min. It was then removed and rinsed twice with overflow water to complete the activation.
[0067] (3) The activated AMB ceramic copper-clad substrate is placed in the electroplating solution for electroplating treatment, and finally cleaned and dried with hot water at 55°C to complete the copper plating.
[0068] The electroplating solution contains the following components at the following concentrations: copper sulfate 100g / L, concentrated sulfuric acid 120mL / L, chloride ions 80ppm, additive I 10mL / L, additive II 0.3g / L, and the solvent is deionized water.
[0069] The electroplating parameters are: temperature 45℃, current density 2A / dm³. 2 The electroplating time was 2.5 hours, the cathode was a copper ball, and the plating thickness was 49 μm, meaning that the average thickness of the AMB ceramic copper-clad substrate after electroplating was 1.936 mm.
[0070] S3: Brush treatment:
[0071] After electroplating, the AMB ceramic copper-clad substrate is polished by nylon brush 1 and nylon brush 2 of a brushing machine. The polishing parameters are: polishing speed of 1.1m / min, current of nylon brush 1 of 1.1A and current of nylon brush 2 of 1A.
[0072] S4: After polishing, a precision circuit pattern is etched on the surface of the AMB ceramic copper-clad substrate. Then, a silver film and a chip are attached to the surface in sequence and heated and cured to obtain a precision AMB ceramic circuit board.
[0073] Example 3: A method for fabricating a precision AMB ceramic circuit board:
[0074] In this embodiment, the actual average thickness of the AMB ceramic copper-clad substrate before improvement was 1.911 mm;
[0075] S1: Grinding process:
[0076] The AMB ceramic copper-clad substrate was mechanically polished by ceramic brush 1 and ceramic brush 2 of a brushing machine. The parameters of the mechanical polishing were: polishing speed of 0.9m / min, current of ceramic brush 1 of 1A, current of ceramic brush 2 of 0.35A, polishing thickness reduction of 22μm, and average thickness of AMB ceramic copper-clad substrate after polishing of 1.889mm.
[0077] S2: Copper plating treatment:
[0078] (1) Place the ground AMB ceramic copper-clad substrate into TD-121 acidic degreasing agent, soak it at 55°C for 2.5 min, take it out, wash it with hot water at 55°C, and then wash it twice with overflow water to complete the degreasing.
[0079] (2) The degreased AMB ceramic copper-clad substrate was placed in 3wt% concentrated sulfuric acid and soaked for 1.5 min. It was then removed and rinsed twice with overflow water to complete the activation.
[0080] (3) The activated AMB ceramic copper-clad substrate is placed in the electroplating solution for electroplating treatment, and finally cleaned and dried with hot water at 55°C to complete the copper plating.
[0081] The electroplating solution contains the following components at the following concentrations: copper sulfate 100g / L, concentrated sulfuric acid 120mL / L, chloride ions 80ppm, additive I 10mL / L, additive II 0.3g / L, and the solvent is deionized water.
[0082] The electroplating parameters are: temperature 45℃, current density 2A / dm³. 2 The electroplating time was 2.5 hours, the cathode was a copper ball, and the plating thickness was 44 μm, meaning that the average thickness of the AMB ceramic copper-clad substrate after electroplating was 1.933 mm.
[0083] S3: Brush treatment:
[0084] After electroplating, the AMB ceramic copper-clad substrate is polished by nylon brush 1 and nylon brush 2 of a brushing machine. The polishing parameters are: polishing speed of 1.1m / min, current of nylon brush 1 of 1.1A and current of nylon brush 2 of 1A.
[0085] S4: After polishing, a precision circuit pattern is etched on the surface of the AMB ceramic copper-clad substrate. Then, a silver film and a chip are attached to the surface in sequence and heated and cured to obtain a precision AMB ceramic circuit board.
[0086] Example 4: A method for fabricating a precision AMB ceramic circuit board:
[0087] In this embodiment, the actual average thickness of the AMB ceramic copper-clad substrate before improvement was 1.914 mm;
[0088] S1: Grinding process:
[0089] The AMB ceramic copper-clad substrate was mechanically polished by ceramic brush 1 and ceramic brush 2 of a brushing machine. The parameters of the mechanical polishing were: polishing speed of 0.9m / min, current of ceramic brush 1 of 1A, current of ceramic brush 2 of 0.35A, polishing thickness reduction of 33μm, and average thickness of AMB ceramic copper-clad substrate after polishing of 1.881mm.
[0090] S2: Copper plating treatment:
[0091] (1) Place the ground AMB ceramic copper-clad substrate into TD-121 acidic degreasing agent, soak it at 55°C for 2.5 min, take it out, wash it with hot water at 55°C, and then wash it twice with overflow water to complete the degreasing.
[0092] (2) The degreased AMB ceramic copper-clad substrate was placed in 3wt% concentrated sulfuric acid and soaked for 1.5 min. It was then removed and rinsed twice with overflow water to complete the activation.
[0093] (3) The activated AMB ceramic copper-clad substrate is placed in the electroplating solution for electroplating treatment, and finally cleaned and dried with hot water at 55°C to complete the copper plating.
[0094] The electroplating solution contains the following components at the following concentrations: copper sulfate 100g / L, concentrated sulfuric acid 120mL / L, chloride ions 80ppm, additive I 10mL / L, additive II 0.3g / L, and the solvent is deionized water.
[0095] The electroplating parameters are: temperature 45℃, current density 2A / dm³. 2 The electroplating time was 2.5 hours, the cathode was a copper ball, and the plating thickness was 50 μm, meaning that the average thickness of the AMB ceramic copper-clad substrate after electroplating was 1.931 mm.
[0096] S3: Brush treatment:
[0097] After electroplating, the AMB ceramic copper-clad substrate is polished by nylon brush 1 and nylon brush 2 of a brushing machine. The polishing parameters are: polishing speed of 1.1m / min, current of nylon brush 1 of 1.1A and current of nylon brush 2 of 1A.
[0098] S4: After polishing, a precision circuit pattern is etched on the surface of the AMB ceramic copper-clad substrate. Then, a silver film and a chip are attached to the surface in sequence and heated and cured to obtain a precision AMB ceramic circuit board.
[0099] Example 5: A method for fabricating a precision AMB ceramic circuit board:
[0100] In this embodiment, the actual average thickness of the AMB ceramic copper-clad substrate before improvement was 1.919 mm;
[0101] S1: Grinding process:
[0102] The AMB ceramic copper-clad substrate was mechanically polished by ceramic brush 1 and ceramic brush 2 of a brushing machine. The parameters of the mechanical polishing were as follows: polishing speed of 0.9m / min, current of ceramic brush 1 of 1A, current of ceramic brush 2 of 0.35A, polishing thickness reduction of 25μm, and average thickness of AMB ceramic copper-clad substrate after polishing of 1.894mm.
[0103] S2: Copper plating treatment:
[0104] (1) Place the ground AMB ceramic copper-clad substrate into TD-121 acidic degreasing agent, soak it at 55°C for 2.5 min, take it out, wash it with hot water at 55°C, and then wash it twice with overflow water to complete the degreasing.
[0105] (2) The degreased AMB ceramic copper-clad substrate was placed in 3wt% concentrated sulfuric acid and soaked for 1.5 min. It was then removed and rinsed twice with overflow water to complete the activation.
[0106] (3) The activated AMB ceramic copper-clad substrate is placed in the electroplating solution for electroplating treatment, and finally cleaned and dried with hot water at 55°C to complete the copper plating.
[0107] The electroplating solution contains the following components at the following concentrations: copper sulfate 100g / L, concentrated sulfuric acid 120mL / L, chloride ions 80ppm, additive I 10mL / L, additive II 0.3g / L, and the solvent is deionized water.
[0108] The electroplating parameters are: temperature 45℃, current density 2A / dm³. 2 The electroplating time was 2.5 hours, the cathode was a copper ball, and the plating thickness was 40 μm, meaning that the average thickness of the AMB ceramic copper-clad substrate after electroplating was 1.934 mm.
[0109] S3: Brush treatment:
[0110] After electroplating, the AMB ceramic copper-clad substrate is polished by nylon brush 1 and nylon brush 2 of a brushing machine. The polishing parameters are: polishing speed of 1.1m / min, current of nylon brush 1 of 1.1A and current of nylon brush 2 of 1A.
[0111] S4: After polishing, a precision circuit pattern is etched on the surface of the AMB ceramic copper-clad substrate. Then, a silver film and a chip are attached to the surface in sequence and heated and cured to obtain a precision AMB ceramic circuit board.
[0112] Example 6: A method for fabricating a precision AMB ceramic circuit board:
[0113] In this embodiment, the actual average thickness of the AMB ceramic copper-clad substrate before improvement was 1.917 mm;
[0114] S1: Grinding process:
[0115] The AMB ceramic copper-clad substrate was mechanically polished by ceramic brush 1 and ceramic brush 2 of a brushing machine. The parameters of the mechanical polishing were as follows: polishing speed of 0.9m / min, current of ceramic brush 1 of 1A, current of ceramic brush 2 of 0.35A, polishing thickness reduction of 30μm, and average thickness of AMB ceramic copper-clad substrate after polishing of 1.887mm.
[0116] S2: Copper plating treatment:
[0117] (1) Place the ground AMB ceramic copper-clad substrate into TD-121 acidic degreasing agent, soak it at 55°C for 2.5 min, take it out, wash it with hot water at 55°C, and then wash it twice with overflow water to complete the degreasing.
[0118] (2) The degreased AMB ceramic copper-clad substrate was placed in 3wt% concentrated sulfuric acid and soaked for 1.5 min. It was then removed and rinsed twice with overflow water to complete the activation.
[0119] (3) The activated AMB ceramic copper-clad substrate is placed in the electroplating solution for electroplating treatment, and finally cleaned and dried with hot water at 55°C to complete the copper plating.
[0120] The electroplating solution contains the following components at the following concentrations: copper sulfate 100g / L, concentrated sulfuric acid 120mL / L, chloride ions 80ppm, additive I 10mL / L, additive II 0.3g / L, and the solvent is deionized water.
[0121] The electroplating parameters are: temperature 45℃, current density 2A / dm³. 2 The electroplating time was 2.5 hours, the cathode was a copper ball, and the plating thickness was 44 μm, meaning that the average thickness of the AMB ceramic copper-clad substrate after electroplating was 1.931 mm.
[0122] S3: Brush treatment:
[0123] After electroplating, the AMB ceramic copper-clad substrate is polished by nylon brush 1 and nylon brush 2 of a brushing machine. The polishing parameters are: polishing speed of 1.1m / min, current of nylon brush 1 of 1.1A and current of nylon brush 2 of 1A.
[0124] S4: After polishing, a precision circuit pattern is etched on the surface of the AMB ceramic copper-clad substrate. Then, a silver film and a chip are attached to the surface in sequence and heated and cured to obtain a precision AMB ceramic circuit board.
[0125] Based on Example 1, a control experiment was conducted, setting up comparative examples 1 to 3:
[0126] Comparative Example 1: Comparative Example 1 is based on Example 1, with the following adjustments: Additive I and Additive II are not added to the electroplating solution, while other processes remain unchanged. Specifically:
[0127] A method for fabricating a precision AMB ceramic circuit board:
[0128] In this embodiment, the actual average thickness of the AMB ceramic copper-clad substrate before improvement was 1.921 mm;
[0129] S1: Grinding process:
[0130] The AMB ceramic copper-clad substrate was mechanically polished by ceramic brush 1 and ceramic brush 2 of a brushing machine. The parameters of the mechanical polishing were as follows: polishing speed of 0.9m / min, current of ceramic brush 1 of 1A, current of ceramic brush 2 of 0.35A, polishing thickness reduction of 25μm, and average thickness of AMB ceramic copper-clad substrate after polishing of 1.896mm.
[0131] S2: Copper plating treatment:
[0132] (1) Place the ground AMB ceramic copper-clad substrate into TD-121 acidic degreasing agent, soak it at 55°C for 2.5 min, take it out, wash it with hot water at 55°C, and then wash it twice with overflow water to complete the degreasing.
[0133] (2) The degreased AMB ceramic copper-clad substrate was placed in 3wt% concentrated sulfuric acid and soaked for 1.5 min. It was then removed and rinsed twice with overflow water to complete the activation.
[0134] (3) The activated AMB ceramic copper-clad substrate is placed in the electroplating solution for electroplating treatment, and finally cleaned and dried with hot water at 55°C to complete the copper plating.
[0135] The electroplating solution contains the following components at the following concentrations: copper sulfate 100g / L, concentrated sulfuric acid 120mL / L, chloride ions 80ppm, and deionized water as the solvent.
[0136] The electroplating parameters are: temperature 45℃, current density 2A / dm³. 2 The electroplating time was 2.5 hours, the cathode was a copper ball, and the plating thickness was 31 μm, meaning that the average thickness of the AMB ceramic copper-clad substrate after electroplating was 1.927 mm.
[0137] S3: Brush treatment:
[0138] After electroplating, the AMB ceramic copper-clad substrate is polished by nylon brush 1 and nylon brush 2 of a brushing machine. The polishing parameters are: polishing speed of 1.1m / min, current of nylon brush 1 of 1.1A and current of nylon brush 2 of 1A.
[0139] S4: After polishing, a precision circuit pattern is etched on the surface of the AMB ceramic copper-clad substrate. Then, a silver film and a chip are attached to the surface in sequence and heated and cured to obtain a precision AMB ceramic circuit board.
[0140] Comparative Example 2: Comparative Example 2 is based on Example 1, with the following adjustment: Additive II is not added to the electroplating solution, while other processes remain unchanged. Specifically:
[0141] A method for fabricating a precision AMB ceramic circuit board:
[0142] In this embodiment, the actual average thickness of the AMB ceramic copper-clad substrate before improvement was 1.923 mm;
[0143] S1: Grinding process:
[0144] The AMB ceramic copper-clad substrate was mechanically polished by ceramic brush 1 and ceramic brush 2 of a brushing machine. The parameters of the mechanical polishing were as follows: polishing speed of 0.9m / min, current of ceramic brush 1 of 1A, current of ceramic brush 2 of 0.35A, polishing thickness reduction of 30μm, and average thickness of AMB ceramic copper-clad substrate after polishing of 1.893mm.
[0145] S2: Copper plating treatment:
[0146] (1) Place the ground AMB ceramic copper-clad substrate into TD-121 acidic degreasing agent, soak it at 55°C for 2.5 min, take it out, wash it with hot water at 55°C, and then wash it twice with overflow water to complete the degreasing.
[0147] (2) The degreased AMB ceramic copper-clad substrate was placed in 3wt% concentrated sulfuric acid and soaked for 1.5 min. It was then removed and rinsed twice with overflow water to complete the activation.
[0148] (3) The activated AMB ceramic copper-clad substrate is placed in the electroplating solution for electroplating treatment, and finally cleaned and dried with hot water at 55°C to complete the copper plating.
[0149] The electroplating solution contains the following components at the following concentrations: copper sulfate 100g / L, concentrated sulfuric acid 120mL / L, chloride ions 80ppm, additive I 10mL / L, and deionized water as the solvent.
[0150] The electroplating parameters are: temperature 45℃, current density 2A / dm³. 2 The electroplating time was 2.5 hours, the cathode was a copper ball, and the plating thickness was 31 μm, meaning that the average thickness of the AMB ceramic copper-clad substrate after electroplating was 1.924 mm.
[0151] S3: Brush treatment:
[0152] After electroplating, the AMB ceramic copper-clad substrate is polished by nylon brush 1 and nylon brush 2 of a brushing machine. The polishing parameters are: polishing speed of 1.1m / min, current of nylon brush 1 of 1.1A and current of nylon brush 2 of 1A.
[0153] S4: After polishing, a precision circuit pattern is etched on the surface of the AMB ceramic copper-clad substrate. Then, a silver film and a chip are attached to the surface in sequence and heated and cured to obtain a precision AMB ceramic circuit board.
[0154] Comparative Example 3: Comparative Example 3 is based on Example 1, with the following adjustment: Additive I is not added to the electroplating solution, while other processes remain unchanged. Specifically:
[0155] A method for fabricating a precision AMB ceramic circuit board:
[0156] In this embodiment, the actual average thickness of the AMB ceramic copper-clad substrate before improvement was 1.918 mm;
[0157] S1: Grinding process:
[0158] The AMB ceramic copper-clad substrate was mechanically polished by ceramic brush 1 and ceramic brush 2 of a brushing machine. The parameters of the mechanical polishing were as follows: polishing speed of 0.9m / min, current of ceramic brush 1 of 1A, current of ceramic brush 2 of 0.35A, polishing thickness reduction of 29μm, and average thickness of AMB ceramic copper-clad substrate after polishing of 1.889mm.
[0159] S2: Copper plating treatment:
[0160] (1) Place the ground AMB ceramic copper-clad substrate into TD-121 acidic degreasing agent, soak it at 55°C for 2.5 min, take it out, wash it with hot water at 55°C, and then wash it twice with overflow water to complete the degreasing.
[0161] (2) The degreased AMB ceramic copper-clad substrate was placed in 3wt% concentrated sulfuric acid and soaked for 1.5 min. It was then removed and rinsed twice with overflow water to complete the activation.
[0162] (3) The activated AMB ceramic copper-clad substrate is placed in the electroplating solution for electroplating treatment, and finally cleaned and dried with hot water at 55°C to complete the copper plating.
[0163] The electroplating solution contains the following components at the following concentrations: copper sulfate 100g / L, concentrated sulfuric acid 120mL / L, chloride ions 80ppm, additive II 0.3g / L, and deionized water as the solvent.
[0164] The electroplating parameters are: temperature 45℃, current density 2A / dm³. 2The electroplating time was 2.5 hours, the cathode was a copper ball, and the plating thickness was 35 μm, meaning that the average thickness of the AMB ceramic copper-clad substrate after electroplating was 1.924 mm.
[0165] S3: Brush treatment:
[0166] After electroplating, the AMB ceramic copper-clad substrate is polished by nylon brush 1 and nylon brush 2 of a brushing machine. The polishing parameters are: polishing speed of 1.1m / min, current of nylon brush 1 of 1.1A and current of nylon brush 2 of 1A.
[0167] S4: After polishing, a precision circuit pattern is etched on the surface of the AMB ceramic copper-clad substrate. Then, a silver film and a chip are attached to the surface in sequence and heated and cured to obtain a precision AMB ceramic circuit board.
[0168] The average thickness changes of the AMB ceramic copper-clad substrates before and after the S1-S2 improvement treatment in Examples 1-6 and Comparative Examples 1-3 are shown in Table 1 below:
[0169] Table 1
[0170] Performance Comparison: The roughness, wire bonding force, hardness, and thermal shock performance of the AMB ceramic copper-clad substrates in Examples 1-6 and Comparative Examples 1-3 before and after the S1-S3 improvement treatment are compared, as shown in Tables 2-5 below:
[0171] Among them, wire bonding force: 300μm aluminum wire was used to perform wire bonding test on the surface of AMB ceramic copper-clad substrate;
[0172] Thermal shock: The AMB ceramic copper-clad substrate is heated at 355℃ for 130 seconds and then cooled at 25℃ for 45 seconds. This is one cycle, which is repeated 15 times. The copper clad layer is observed to see if it peels off or other abnormalities occur.
[0173] Table 2 Roughness Comparison
[0174] Table 3 Comparison of Stringing Strength
[0175] Table 4 Hardness (HV10) Comparison
[0176] Table 5 Comparison of thermal shock
[0177] The test results in Tables 2 to 5 above show that:
[0178] (1) The relevant data of the examples are better than those of the comparative examples, indicating that additive I and additive II play an important role in copper electroplating;
[0179] The following comparisons only include the relevant test results of the embodiments, as shown in (2)(3)(4)(5):
[0180] (2) In terms of roughness: The surface of the AMB ceramic copper-clad substrate, which has undergone grinding, electroplating, and polishing, is smoother and denser, with a smaller roughness value and Ra. avg =0.240μm>0.964μm, Rz avg =2.344μm > 7.167μm, Rmax avg = 4.448μm > 11.514μm;
[0181] (3) In terms of wire bonding force: AMB ceramic copper-clad substrates that have undergone grinding, electroplating, and polishing have superior wire bonding force. avg The value is 1635.7 g / mm > 1386.0 g / mm;
[0182] (4) In terms of hardness: AMB ceramic copper-clad substrates that have undergone grinding, electroplating, and polishing have higher hardness. avg =78.94Gpa > 46.56Gpa;
[0183] (5) Regarding thermal shock: Neither of them showed any signs of detachment or abnormality;
[0184] In summary, conventional AMB ceramic copper-clad laminates, after vacuum soldering, naturally produce irregular grains on the copper foil surface. These grains have high roughness and poor density, leading to varying degrees of chip misalignment, weak bonding, and even detachment during subsequent chip attachment. This invention, however, takes a novel approach. Through a three-step process of "grinding + copper plating + polishing," the surface of the copper foil sintered using the traditional AMB process is improved, altering the copper foil morphology to achieve a grain-free, smooth, and dense surface. This results in a stronger bond with the chip, resolving issues of chip misalignment, weak bonding, and detachment. This method can meet the packaging needs of different customers.
[0185] 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 invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
Claims
1. A method for fabricating a precision AMB ceramic circuit board, characterized in that: Includes the following steps: S1: Grinding process of AMB ceramic copper-clad substrate; S2: After S1, copper plating is performed on the AMB ceramic copper-clad substrate; S3: After S2, the AMB ceramic copper-clad substrate is polished and brushed. S4: After S3, a precision circuit pattern is etched on the surface of the AMB ceramic copper-clad substrate. Then, a silver film and a chip are attached to the surface in sequence and heated and cured to obtain a precision AMB ceramic circuit board.
2. The method for preparing a precision AMB ceramic circuit board according to claim 1, characterized in that: The grinding process is carried out by mechanical grinding, specifically: the AMB ceramic copper-clad substrate is mechanically ground by ceramic brush 1 and ceramic brush 2 of the brushing machine. The parameters for mechanical grinding are as follows: grinding speed is 0.8 to 1.0 m / min, current of ceramic brush 1 is 0.9 to 1.1 A, current of ceramic brush 2 is 0.3 to 0.4 A, and grinding thickness is 15 to 35 μm.
3. The method for preparing a precision AMB ceramic circuit board according to claim 1, characterized in that: The copper plating is performed by electroplating. The specific process is as follows: the ground AMB ceramic copper-clad substrate is first degreased and activated in sequence, then placed in the electroplating solution for electroplating, and finally cleaned and dried with hot water at 50-60°C to complete the copper plating.
4. The method for preparing a precision AMB ceramic circuit board according to claim 3, characterized in that: The electroplating solution comprises the following components at the following concentrations: copper sulfate 80–120 g / L, concentrated sulfuric acid 100–140 mL / L, chloride ions 60–100 ppm, additive I 5–15 mL / L, additive II 0.2–0.4 g / L, and deionized water as the solvent.
5. The method for preparing a precision AMB ceramic circuit board according to claim 4, characterized in that: The preparation method of additive I is as follows: (1) 5-bromo-2,2'-bipyridine is added to anhydrous ethanol and stirred to dissolve, so as to obtain an ethanol solution of 5-bromo-2,2'-bipyridine; (2) fatty alcohol ethoxy compound is added to water and stirred to dissolve, so as to obtain an aqueous solution of fatty alcohol ethoxy compound; (3) the ethanol solution of 5-bromo-2,2'-bipyridine and the aqueous solution of fatty alcohol ethoxy compound are thoroughly mixed and then 50wt% ethanol solution is added to make up the volume to obtain additive I; Additive I comprises the following components at the following concentrations: 8–16 g / L of 5-bromo-2,2'-bipyridine, 24–48 g / L of fatty alcohol ethoxy compounds, and a 50 wt% ethanol solution as the solvent.
6. The method for preparing a precision AMB ceramic circuit board according to claim 5, characterized in that: The mass ratio of the 5-bromo-2,2'-bipyridine to the fatty alcohol ethoxy compound is 1:
3.
7. The method for preparing a precision AMB ceramic circuit board according to claim 4, characterized in that: The preparation method of additive II is as follows: (1) 4'-(3-pyridyl)-2,2':6',2”-terpyridine is added to dichloromethane and stirred to dissolve, so as to obtain a dichloromethane solution of 4'-(3-pyridyl)-2,2':6',2”-terpyridine; (2) cerium nitrate is added to methanol and stirred to dissolve, and then the dichloromethane solution of 4'-(3-pyridyl)-2,2':6',2”-terpyridine is slowly added dropwise. After stirring and mixing for 1 to 2 hours, the filtrate is collected by filtration. After standing for 48 to 96 hours, the crystals are collected to obtain additive II. The mass ratio of 4'-(3-pyridyl)-2,2':6',2”-terpyridine to cerium nitrate is 2:
1.
8. The method for preparing a precision AMB ceramic circuit board according to claim 3, characterized in that: The electroplating parameters are: temperature 40–50°C, current density 1–3 A / dm³. 2 The electroplating time is 2-3 hours, the cathode is copper, and the plating thickness is 25-50 μm.
9. The method for preparing a precision AMB ceramic circuit board according to claim 1, characterized in that: The polishing process specifically involves the following steps: After copper plating, the AMB ceramic copper-clad substrate is polished by non-woven brush 1 and non-woven brush 2 of a brushing machine. The polishing parameters are as follows: the polishing speed is 1.0 to 1.2 m / min, the current of non-woven brush 1 is 1.0 to 1.2 A, and the current of non-woven brush 2 is 0.9 to 1.1 A.
10. A precision AMB ceramic circuit board prepared by any one of the preparation methods of a precision AMB ceramic circuit board according to any one of claims 1 to 9.