A preparation method of a ferrite-based thin film circuit product

Abstract

A preparation method of a ferrite-based thin film circuit product, which relates to the technical field of microwave integrated circuit systems, solves the technical problem of poor film layer adhesion of existing ferrite-based thin film circuit products. It includes a ferrite substrate, a transition layer, a prefabricated layer, a conductor layer, a barrier layer, and a welding layer. In the present invention, the adhesion between the film layers of the thin film circuit product and between the film layer and the substrate can be effectively improved by cleaning the substrate. At the same time, the production process is simplified and the production cycle is shortened. The adhesion between the film layers of the thin film circuit product is effectively improved through the activation treatment between the prefabricated layer and each film layer, reducing the number of photolithography and film layer deposition times, simplifying the production process, and shortening the production cycle.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave integrated circuit systems, and particularly relates to a method for preparing a ferrite-based thin film circuit product. Background Art

[0002] Ferrite is a non-metallic magnetic material, which is a composite oxide mainly composed of iron oxide and other iron-group or rare-earth-group oxides (such as nickel oxide, zinc oxide, magnesium oxide, barium oxide, etc.). It is widely used as a magnetic medium in civilian equipment and military systems. Ferrite materials belong to semiconductors in terms of electrical conductivity, and their resistivity is higher than that of metal magnetic materials. Under high-frequency use conditions, ferrite has a high magnetic permeability. At microwave frequencies, metal magnetic materials cannot be used normally due to severe eddy current effects and skin effects, but ferrite materials can be made into good microwave devices, so they are widely used in the microwave field.

[0003] Ferrite-based metallized thin film circuit products are one of the indispensable parts in microwave integrated circuit systems and have a very broad market in both civilian equipment and the military. With the advent of the 5G era, ferrite products not only require more stable and reliable performance, but also need to be smaller in size and higher in integration. Traditional ferrite-based thin film circuit products mainly consist of a transition layer, a conductor layer, a barrier layer, and a welding layer. First, a transition layer is deposited on a ferrite substrate, and then through multiple photolithography and deposition processes, the pattern of the thin film circuit appears on the transition layer. Then, the transition layer is removed using etching technology, and finally, independent thin film circuit products are formed by cutting.

[0004] However, due to the differences in the performance parameters between the ferrite magnetic material and the metallized film layer in ferrite-based thin film circuit products, there will be a problem of poor film layer adhesion. Multiple photolithography and deposition processes not only complicate the process flow, but also increase the error of their pattern size and the production cycle.

[0005] Therefore, in order to solve the above technical problems, a method for preparing a ferrite-based thin film circuit product is designed. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for preparing a ferrite-based thin film circuit product to solve the technical problem of poor film layer adhesion of ferrite-based thin film circuit products in the background art.

[0007] The present invention specifically adopts the following technical solutions to achieve the above purpose:

[0008] A method for preparing a ferrite-based thin film circuit product, including a ferrite substrate, a transition layer, a prefabricated layer, a conductor layer, a barrier layer, and a welding layer. The specific preparation method is as follows:

[0009] Step (1): Clean the ferrite substrate by ultrasonically cleaning and soaking it in a solution, where the solution can be one of a cleaning agent, an organic solvent, a dilute acid solution, a dilute alkali solution, and deionized water;

[0010] Step (2): Prepare a transition layer and a prefabricated layer on the ferrite substrate and bake the transition layer and the prefabricated layer. The preparation methods of the transition layer and the prefabricated layer include one of vacuum evaporation, sputtering, and chemical vapor deposition. The transition layer material can be one of chromium, nickel, aluminum, and titanium. The conductor layer material can be selected from copper and aluminum. The prefabricated layer material can be selected from copper and aluminum. The baking temperature range of the transition layer and the prefabricated layer is 100°C to 300°C, and the baking time range is 15 min to 60 min. The baking method of the transition layer and the prefabricated layer can be selected from oven baking, furnace tube baking, and baking table baking. The thickness range of the transition layer is 50 nm to 200 nm, and the thickness range of the prefabricated layer is 200 nm to 500 nm;

[0011] Step (3): Cover the non-graphic part of the surface of the prefabricated layer with photoresist through a lithography process. After activating the surface of the prefabricated layer, deposit the conductor layer. The thickness range of the photoresist is 6 to 15 μm. The preparation method of the conductor layer is one of electroplating, electroless plating, and physical vapor deposition. The thickness of the conductor layer is 3 to 10 μm. The conductor layer material can be selected from copper and aluminum. The activation treatment method can be one of acidification treatment and polishing treatment. The activation treatment solution for the activation treatment can be selected from nitric acid, sulfuric acid, and hydrochloric acid. The concentration range of the activation treatment solution is 0.01% to 10%;

[0012] Step (4): After activating the surface of the conductor layer, deposit the barrier layer and the welding layer. The preparation method of the conductor layer includes one of electroplating, electroless plating, and physical vapor deposition. The preparation methods of the barrier layer and the welding layer include one of electroplating, electroless plating, physical vapor deposition, and chemical vapor deposition. The thickness range of the barrier layer is 0.3 to 2 μm. The barrier layer material can be selected from nickel and titanium. The thickness range of the welding layer is 0.5 to 5 μm. The welding layer material can be selected from gold and silver. The activation treatment method can be one of acidification treatment and polishing treatment. The activation treatment solution for the activation treatment can be selected from nitric acid, sulfuric acid, and hydrochloric acid. The concentration range of the activation treatment solution is 0.01% to 10%;

[0013] Step (5), after the deposition is completed, remove the photoresist on the non-graphic part of the surface of the prefabricated layer, and bake the film layer. The photoresist removal method includes one of ultrasonic treatment, heating and ultrasonic treatment, soaking, and heating and soaking. The heating temperature range in the photoresist removal method is 40°C to 70°C, the ultrasonic time range in the photoresist removal method is 5 minutes to 30 minutes, the baking temperature range is 100°C to 300°C, the baking time range is 30 minutes to 120 minutes, and the baking method can be selected from one of oven baking, furnace tube baking, and baking table baking;

[0014] Step (6), etch the non-graphic part of the surface of the prefabricated layer to insulate the non-graphic part of the substrate. The etching method for the non-graphic part of the surface of the prefabricated layer includes one of dry etching and wet etching. The etching time range for the non-graphic part of the surface of the prefabricated layer is 30 minutes to 120 minutes;

[0015] Step (7), cut the whole ferrite substrate into independent thin-film circuit products. The cutting method for the ferrite substrate includes one of mechanical cutting and laser cutting.

[0016] Advantages of the present invention:

[0017] 1. By cleaning the substrate, the present invention can effectively improve the adhesion between the film layers of the thin-film circuit product and between the film layer and the substrate, while simplifying the production process and shortening the production cycle.

[0018] 2. Through the activation treatment between the prefabricated layer and each film layer, the present application effectively improves the adhesion between the film layers of the thin-film circuit product.

[0019] 3. The present application reduces the number of photolithography and film deposition times, simplifies the production process, and shortens the production cycle. Description of the drawings

[0020] Figure 1 It is a schematic structural diagram of the present invention;

[0021] Figure 2 It is a schematic structural diagram of the adjustment component of the present invention;

[0022] Reference numerals: 1-ferrite substrate, 2-transition layer, 3-prefabricated layer, 4-photoresist, 5-conductor layer, 6-barrier layer, 7-welding layer. Detailed implementation manners

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0025] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, the terms "first", "second", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0026] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "inner", "outer", "upper", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention.

[0027] Embodiment 1

[0028] As Figure 1-2 shown, a method for preparing a ferrite-based thin film circuit product includes a ferrite substrate, a transition layer, a prefabricated layer, a conductor layer, a barrier layer, and a welding layer. The specific preparation method is as follows:

[0029] Step (1): Clean the ferrite substrate by ultrasonic treatment and immersion of the ferrite substrate in a solution, where the solution includes a dilute acid solution.

[0030] Step (2): Prepare a transition layer and a prefabricated layer on the ferrite substrate, and bake the transition layer and the prefabricated layer. The preparation methods of the transition layer and the prefabricated layer include one of vacuum evaporation, sputtering, and chemical vapor deposition. The material of the transition layer is one of chromium, nickel, aluminum, and titanium. The material of the prefabricated layer is copper. The baking temperature range of the transition layer and the prefabricated layer is 100 °C, and the baking time range is 15 min. The baking method of the transition layer and the prefabricated layer can be selected as oven baking. The thickness of the transition layer is 50 nm, and the thickness of the prefabricated layer is 200 nm;

[0031] Step (3): Cover the non-graphic part of the surface of the prefabricated layer with photoresist through a photolithography process. After activating the surface of the prefabricated layer, deposit the conductor layer. The thickness range of the photoresist is 6 μm. The preparation method of the conductor layer is electroplating; the thickness of the conductor layer is 3 μm, the material of the conductor layer is copper, the activation treatment method is acidification treatment, the activation treatment solution can be selected as nitric acid, and the concentration range of the activation treatment solution is 0.01%;

[0032] Step (4): After activating the surface of the conductor layer, deposit the barrier layer and the solder layer. The preparation method of the conductor layer is electroplating, and the preparation methods of the barrier layer and the solder layer are electroplating. The thickness range of the barrier layer is 0.3 μm, the material of the barrier layer can be selected as nickel, the thickness range of the solder layer is 0.5 μm, the material of the solder layer can be selected as gold, the activation treatment method is acidification treatment, the activation treatment solution is selected as nitric acid, the concentration range of the activation treatment solution is 0.01%, and the material of the conductor layer is copper;

[0033] Step (5): After the deposition is completed, remove the photoresist on the non-graphic part of the surface of the prefabricated layer, and bake the film layer. The method for removing the photoresist is ultrasonic. The heating temperature range in the method for removing the photoresist is 40 °C, and the ultrasonic time range in the method for removing the photoresist is 5 min;

[0034] Step (6): Etch the non-graphic part of the surface of the prefabricated layer to insulate the non-graphic part of the substrate. The method for etching the non-graphic part of the surface of the prefabricated layer is dry etching, and the etching time range of the non-graphic part of the surface of the prefabricated layer is 30 min;

[0035] Step (7): Cut the whole ferrite substrate into independent thin-film circuit products. The cutting method of the ferrite substrate is mechanical cutting.

[0036] Example 2

[0037] A method for preparing a ferrite-based thin-film circuit product, including a ferrite substrate, a transition layer, a prefabricated layer, a conductor layer, a barrier layer, and a solder layer. The specific preparation method is as follows:

[0038] Step (1): Clean the ferrite substrate. Use a solution to ultrasonically clean and soak the ferrite substrate. The solution is deionized water;

[0039] Step (2): Prepare a transition layer and a prefabricated layer on the ferrite substrate, and bake the transition layer and the prefabricated layer. The preparation method of the transition layer and the prefabricated layer is chemical vapor deposition. The material of the transition layer is titanium. The baking temperature range of the transition layer and the prefabricated layer is 300 °C, the baking time range is 60 min, the baking method of the transition layer and the prefabricated layer can be selected as baking on a baking table. The thickness of the transition layer is 200 nm, and the thickness of the prefabricated layer is 500 nm;

[0040] Step (3): Through the photolithography process, the non-graphic part of the surface of the prefabricated layer is covered with photoresist. After activating the surface of the prefabricated layer, deposit the conductor layer. The thickness range of the photoresist is 15 μm. The preparation method of the conductor layer is one of the physical vapor deposition methods; the thickness of the conductor layer is 10 μm, and the material of the conductor layer is one of aluminum. The activation treatment method is one of the grinding treatments. The activation treatment solution for the activation treatment is selected from hydrochloric acid, and the concentration range of the activation treatment solution is 10%;

[0041] Step (4): After activating the surface of the conductor layer, deposit the barrier layer and the welding layer. The preparation method of the conductor layer includes physical vapor deposition. The preparation methods of the barrier layer and the welding layer are in the chemical vapor deposition method. The thickness range of the barrier layer is 2 μm, and the material of the barrier layer is selected from one of titanium. The thickness range of the welding layer is 05 μm, and the material of the welding layer is selected from one of silver. The activation treatment method is one of the grinding treatments. The activation treatment solution for the activation treatment is selected from one of hydrochloric acids, and the concentration range of the activation treatment solution is 10%. The material of the conductor layer is aluminum, and the material of the prefabricated layer is aluminum;

[0042] Step (5): After the deposition is completed, remove the photoresist on the non-graphic part of the surface of the prefabricated layer, and bake the film layer. The method for removing the photoresist is heating and soaking. The heating temperature range in the method for removing the photoresist is 70 °C, the baking time range is 120 min, and the baking method is baking on a baking table;

[0043] Step (6): Etch the non-graphic part of the surface of the prefabricated layer to insulate the non-graphic part of the substrate. The method for etching the non-graphic part of the surface of the prefabricated layer is wet etching. The etching time for the non-graphic part of the surface of the prefabricated layer is 120 min;

[0044] Step (7): Cut the entire ferrite substrate into independent thin-film circuit products. The cutting method of the ferrite substrate is one of the laser cutting methods.

[0045] Example 3

[0046] A preparation method of a ferrite-based thin-film circuit product, including a ferrite substrate, a transition layer, a prefabricated layer, a conductor layer, a barrier layer, and a welding layer. The specific preparation method is as follows:

[0047] Step (1): Clean the ferrite substrate, and perform ultrasonic treatment and soaking on the ferrite substrate using a solution, where the solution is a dilute alkali solution;

[0048] Step (2): Prepare a transition layer and a prefabricated layer on the ferrite substrate, and bake the transition layer and the prefabricated layer. The preparation method of the transition layer and the prefabricated layer is sputtering. The thickness range of the transition layer is 80 nm, the thickness range of the prefabricated layer is 400 nm, the material of the transition layer is nickel, the material of the prefabricated layer is copper, the baking temperature range of the transition layer and the prefabricated layer is 200 °C, the baking time of the transition layer and the prefabricated layer is 40 min, and the baking method of the transition layer and the prefabricated layer is furnace tube baking;

[0049] Step (3): Through a lithography process, the non-graphic part of the surface of the prefabricated layer is covered with photoresist. After activating the surface of the prefabricated layer, deposit the conductor layer. The thickness of the photoresist is 10 μm, and the preparation method of the conductor layer is electroplating; the thickness of the conductor layer is 6 μm, the material of the conductor layer is copper, the activation treatment method is acidification treatment, the activation treatment solution for the activation treatment is hydrochloric acid, and the concentration of the activation treatment solution is 1%;

[0050] Step (4): After activating the surface of the conductor layer, deposit the barrier layer and the welding layer. The preparation method of the conductor layer is electroplating, and the preparation methods of the barrier layer and the welding layer are electroplating. The thickness range of the barrier layer is 1 μm, the material of the barrier layer is nickel, the thickness of the welding layer is 3 μm, the material of the welding layer is gold, the activation treatment method is acidification treatment, the activation treatment solution for the activation treatment is hydrochloric acid, the concentration of the activation treatment solution is 1%, and the material of the conductor layer is selected as copper;

[0051] Step (5): After completion of the deposition, remove the photoresist on the non-graphic part of the surface of the prefabricated layer, and bake the film layer. The method for removing the photoresist is heating and ultrasonic treatment. The heating temperature range in the method for removing the photoresist is 50 °C, the ultrasonic time range in the method for removing the photoresist is 20 min, and the baking method is furnace tube baking;

[0052] Step (6): Etch the non-graphic part of the surface of the prefabricated layer to insulate the non-graphic part of the substrate. The method for etching the non-graphic part of the surface of the prefabricated layer is dry etching, and the etching time range of the non-graphic part of the surface of the prefabricated layer is 60 min;

[0053] Step (7): Cut the entire ferrite substrate into independent thin-film circuit products, and the ferrite substrate cutting method is mechanical cutting.

[0054] The following table shows the comparison data for conventional products and this application, which are as follows:

[0055]

[0056] As can be seen from the above table, the adhesion of the film layer is significantly better than that of the control group in the three groups of embodiments.

[0057] As is known by common technical knowledge, the present invention can be implemented by other embodiments that do not depart from its spirit or essential features. Therefore, the above-disclosed embodiments are illustrative in all aspects and not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are encompassed by the present invention.

Claims

1. A method for preparing a ferrite-based thin-film circuit product, characterized in that, it includes a ferrite substrate, a transition layer, a prefabrication layer, a conductor layer, a barrier layer, and a welding layer. The specific preparation method is as follows: Step (1): Clean the ferrite substrate, and ultrasonically clean and soak the ferrite substrate with a solution. Step (2): Prepare a transition layer and a prefabrication layer on the ferrite substrate, and bake the transition layer and the prefabrication layer. Step (3): Through a photolithography process, the non-graphic part of the surface of the prefabrication layer is covered with photoresist. After activating the surface of the prefabrication layer, deposit the conductor layer. Step (4): After activating the surface of the conductor layer, deposit the barrier layer and the welding layer. Step (5): After completion of deposition, remove the photoresist on the non-graphic part of the surface of the prefabrication layer, and bake the film layer. Step (6): Etch the non-graphic part of the surface of the prefabrication layer to insulate the non-graphic part of the substrate. Step (7): Cut the entire ferrite substrate into independent thin-film circuit products. The ferrite substrate cutting method includes one of mechanical cutting and laser cutting.

2. The method for preparing a ferrite-based thin-film circuit product according to claim 1, characterized in that, the solution includes one of a cleaning agent, an organic solvent, a dilute acid solution, a dilute alkali solution, and deionized water.

3. The method for preparing a ferrite-based thin-film circuit product according to claim 1, characterized in that, the preparation method of the transition layer and the prefabrication layer includes one of vacuum evaporation, sputtering, and chemical vapor deposition. The preparation method of the conductor layer includes one of electroplating, electroless plating, and physical vapor deposition.

4. The method for preparing a ferrite-based thin-film circuit product according to claim 1, characterized in that, the thickness range of the transition layer is 50nm - 200nm, and the thickness range of the prefabrication layer is 200nm - 500nm.

5. The method for preparing a ferrite-based thin-film circuit product according to claim 1, characterized in that, the material of the transition layer is one of chromium, nickel, aluminum, and titanium. The material of the conductor layer can be selected from one of copper and aluminum. The material of the prefabrication layer is one of copper and aluminum. The baking temperature range of the transition layer and the prefabrication layer is 100°C - 300°C. The baking time range of the transition layer and the prefabrication layer is 15min - 60min. The baking method of the transition layer and the prefabrication layer can be selected from one of oven baking, furnace tube baking, and baking table baking.

6. The method for preparing a ferrite-based thin-film circuit product according to claim 1, characterized in that, in step (3), the thickness range of the photoresist is 6 - 15um. The preparation method of the conductor layer is one of electroplating, electroless plating, and physical vapor deposition. The thickness of the conductor layer is 3 - 10um, the thickness of the conductor layer is 6um, and the material of the conductor layer is one of copper and aluminum.

7. The method for preparing a ferrite-based thin-film circuit product according to claim 1, characterized in that, In the steps (3) and (4), the activation treatment method is one of acidification treatment and polishing treatment. The activation treatment solution for the activation treatment can be selected from nitric acid, sulfuric acid, and hydrochloric acid. The concentration range of the activation treatment solution is 0.01% - 10%.

8. A method for preparing a ferrite-based thin film circuit product according to claim 1, wherein, in the step (4), the preparation methods of the barrier layer and the welding layer include one of electroplating, electroless plating, physical vapor deposition, and chemical vapor deposition. The thickness range of the barrier layer is 0.3 - 2 μm, the barrier layer material can be selected from nickel and titanium, the thickness range of the welding layer is 0.5 - 5 μm, and the welding layer material can be selected from gold and silver.

9. A method for preparing a ferrite-based thin film circuit product according to claim 1, wherein, in the step (5), the photoresist removal methods include one of ultrasonic treatment, heating and ultrasonic treatment, soaking, and heating and soaking. The heating temperature range in the photoresist removal method is 40°C - 70°C, the ultrasonic time range in the photoresist removal method is 5 min - 30 min, the baking temperature range is 100°C - 300°C, the baking time range is 30 min - 120 min, and the baking method can be selected from oven baking, furnace tube baking, and baking table baking.

10. A method for preparing a ferrite-based thin film circuit product according to claim 1, wherein, in the step (6), the etching method for the non-graphic part on the surface of the prefabricated layer includes one of dry etching and wet etching. The etching time range for the non-graphic part on the surface of the prefabricated layer is 30 min - 120 min.

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