Preparation method of circuit board

Abstract

The invention discloses a preparation method of a circuit board. The preparation method comprises the following steps: cleaning and drying a substrate of the circuit board; depositing and forming a metal transition layer on the surface of the circuit board substrate; depositing and forming a conductive layer on the surface of the metal transition layer; pasting a photosensitive material on the surface of the conductive layer, and performing exposure, development and cleaning treatment on the circuit board substrate by using a mask with a pattern; carrying out etching treatment on the uncovered conductive layer on the circuit board substrate by adopting ion etching so as to form a conductive circuit on the circuit board substrate; and carrying out film stripping treatment on the circuit board substrate so as to remove the residual photosensitive material on the circuit board substrate. According to the technical scheme, the conductive layer with small thickness can be obtained by changing the laying mode of the conductive layer on the circuit board, so that the circuit board meets the requirement of equipment miniaturization.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board manufacturing, and in particular to a method for preparing a circuit board. Background Art

[0002] As the size of electronic devices becomes smaller and smaller, the size of integrated circuits is also getting smaller and smaller. Correspondingly, the conductive layers laid in integrated circuits are becoming thinner and thinner. However, the conductive layers laid in traditional circuit boards are generally thicker, which is far from meeting the needs of device miniaturization. Summary of the invention

[0003] The purpose of an embodiment of the present invention is to provide a method for preparing a circuit board, which can obtain a conductive layer with a small thickness by changing the laying method of the conductive layer on the circuit board, so that the circuit board meets the requirements of miniaturization of the equipment.

[0004] In order to achieve the above object, an embodiment of the present invention provides a method for preparing a circuit board, comprising:

[0005] Clean and dry the circuit board substrate;

[0006] Depositing a metal transition layer on the surface of the circuit board substrate;

[0007] Depositing a conductive layer on the surface of the metal transition layer;

[0008] Pasting a photosensitive material on the surface of the conductive layer, and using a mask with a pattern to expose, develop and clean the circuit board substrate;

[0009] Etching the uncovered conductive layer on the circuit board substrate by ion etching to form a conductive circuit on the circuit board substrate;

[0010] The circuit board substrate is subjected to a film stripping process to remove the remaining photosensitive material on the circuit board substrate.

[0011] Furthermore, the cleaning and drying of the circuit board substrate specifically includes:

[0012] Use deionized water to clean the circuit board substrate for 30 minutes;

[0013] Use a nitrogen gun to dry the cleaned circuit board substrate.

[0014] Furthermore, the step of depositing a metal transition layer on the surface of the circuit board substrate specifically includes:

[0015] Place the circuit board substrate in a vacuum chamber and maintain the vacuum degree at 0.1-0.2 Pa;

[0016] Apply a power greater than 300W to the magnetron sputtering target, apply a bias voltage greater than 150V to the circuit board substrate, start the magnetron sputtering target to sputter for 25 to 40 minutes, so as to deposit a metal transition layer on the surface of the circuit board substrate; wherein the magnetron sputtering target is a chromium target or a titanium target.

[0017] Furthermore, the thickness of the metal transition layer is 10-15 nm.

[0018] Furthermore, the step of depositing a conductive layer on the surface of the metal transition layer specifically includes:

[0019] The vacuum degree in the vacuum chamber is maintained at 0.1-0.3 Pa, and copper target sputtering is started for 20-30 minutes to complete copper plating, so as to deposit a conductive layer on the surface of the metal transition layer; wherein the conductive layer is a copper foil layer, the copper plating power is 9-10 kW, and the ion bombardment current is 20-25 A.

[0020] Furthermore, the thickness of the conductive layer is 20 nm.

[0021] Furthermore, the gas used for ion etching is a mixed gas of carbon tetrafluoride and oxygen, and the ratio of carbon tetrafluoride to oxygen is 8:2.

[0022] Furthermore, the flow rate of the mixed gas is 800-1000 sccm, the chamber temperature is 20-25° C., the chamber pressure is 20-25 mtorr, the source power is 200-250 W, and the bias power is 150 W.

[0023] Furthermore, the etching time of the ion etching is 30 to 40 minutes.

[0024] Furthermore, the stripping process of the circuit board substrate specifically includes:

[0025] Soak the circuit board substrate in a 6% to 10% sodium hydroxide solution for 30 minutes;

[0026] The immersed circuit board substrate is cleaned with deionized water.

[0027] Compared with the prior art, the embodiment of the present invention provides a method for preparing a circuit board, first, the circuit board substrate is cleaned and dried; then, a metal transition layer is deposited on the surface of the circuit board substrate, and a conductive layer is deposited on the surface of the metal transition layer; then, a photosensitive material is pasted on the surface of the conductive layer, and the circuit board substrate is exposed, developed and cleaned using a mask with a pattern; then, the uncovered conductive layer on the circuit board substrate is etched using ion etching to form a conductive circuit on the circuit board substrate; finally, the circuit board substrate is stripped to remove the remaining photosensitive material on the circuit board substrate. The embodiment of the present invention can obtain a conductive layer with a small thickness by changing the laying method of the conductive layer on the circuit board, so that the circuit board meets the requirements of equipment miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flow chart of a preferred embodiment of a method for preparing a circuit board provided by the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this technical field without creative work are within the scope of protection of the present invention.

[0030] The present invention provides a method for preparing a circuit board. Figure 1 FIG. 1 is a flow chart of a preferred embodiment of a method for preparing a circuit board provided by the present invention, wherein the method comprises steps S11 to S16:

[0031] Step S11, cleaning and drying the circuit board substrate;

[0032] Step S12, depositing a metal transition layer on the surface of the circuit board substrate;

[0033] Step S13, depositing a conductive layer on the surface of the metal transition layer;

[0034] Step S14, pasting a photosensitive material on the surface of the conductive layer, and using a mask with a pattern to expose, develop and clean the circuit board substrate;

[0035] Step S15, etching the uncovered conductive layer on the circuit board substrate by ion etching to form a conductive circuit on the circuit board substrate;

[0036] Step S16: stripping the circuit board substrate to remove the remaining photosensitive material on the circuit board substrate.

[0037] In the specific implementation, first, the circuit board substrate is cleaned. The purpose of cleaning is to remove tiny dust and oily water attached to the surface of the circuit board substrate. After cleaning, the circuit board substrate is dried; then, a metal transition layer is deposited on the surface of the circuit board substrate, and a conductive layer is continuously deposited on the surface of the metal transition layer. The metal transition layer is plated on the surface of the circuit board substrate and is located between the circuit board substrate and the conductive layer, so that the conductive layer and the circuit board substrate can be better bonded together; then, a photosensitive material (for example, film, etc.) is pasted on the surface of the conductive layer, and the circuit board substrate is exposed and developed using a mask with a pattern (i.e., a mask). It can be understood that by irradiating with UV light through the mask with a pattern, the light-transmitting part on the surface of the conductive layer (i.e., the part that is not blocked by the mask) is photosensitized. When the material is irradiated by UV light, its properties change, and the properties of the photosensitive material on the non-translucent part of the surface of the conductive layer (i.e., the part blocked by the mask) are different. Accordingly, the translucent part forms a circuit image, and then the circuit board substrate is placed in a cleaning solution for cleaning to wash away the part other than the circuit image. In this way, two parts, covered by the photosensitive material and not covered by the photosensitive material, are formed on the surface of the conductive layer; then, the conductive layer on the circuit board substrate not covered by the photosensitive material is etched by an ion etching method, the conductive layer not covered by the photosensitive material is bombarded away, and the conductive layer covered by the photosensitive material is retained, thereby forming a conductive circuit on the circuit board substrate; finally, the circuit board substrate is stripped to remove the photosensitive material remaining on the circuit board substrate after etching, and a circuit board that meets the needs of equipment miniaturization is obtained accordingly.

[0038] In another preferred embodiment, the cleaning and drying of the circuit board substrate specifically includes:

[0039] Use deionized water to clean the circuit board substrate for 30 minutes;

[0040] Use a nitrogen gun to dry the cleaned circuit board substrate.

[0041] Specifically, in combination with the above embodiment, when cleaning and drying the circuit board substrate, the circuit board substrate can be first rinsed with deionized water, and after cleaning for 30 minutes, the cleaned circuit board substrate can be blown dry with a nitrogen (N2) gun.

[0042] In another preferred embodiment, the step of depositing a metal transition layer on the surface of the circuit board substrate specifically includes:

[0043] Place the circuit board substrate in a vacuum chamber and maintain the vacuum degree at 0.1-0.2 Pa;

[0044] Apply a power greater than 300W to the magnetron sputtering target, apply a bias voltage greater than 150V to the circuit board substrate, start the magnetron sputtering target to sputter for 25 to 40 minutes, so as to deposit a metal transition layer on the surface of the circuit board substrate; wherein the magnetron sputtering target is a chromium target or a titanium target.

[0045] Specifically, in combination with the above embodiments, when a metal transition layer is deposited on the surface of a circuit board substrate, the circuit board substrate can be placed in a vacuum chamber, the vacuum degree in the vacuum chamber is maintained at 0.1Pa to 0.2Pa, the magnetron sputtering power supply is turned on, the current is conducted to the magnetron sputtering cathode of the magnetron sputtering target, a DC power supply power greater than 300W is applied to the magnetron sputtering target, and a pulse bias voltage greater than 150V is applied to the circuit board substrate, and the magnetron sputtering target is started to sputter for 25min to 40min to deposit a metal transition layer on the surface of the circuit board substrate.

[0046] It should be noted that, in the embodiment of the present invention, the magnetron sputtering target is a chromium (Cr) target or a titanium (Ti) target, and the corresponding metal transition layer mainly includes a series of metals such as Cr or Ti.

[0047] Exemplarily, the vacuum degree in the vacuum chamber can be 0.1Pa, 0.11Pa, 0.12Pa, 0.13Pa, 0.14Pa, 0.15Pa, 0.16Pa, 0.17Pa, 0.18Pa, 0.19Pa or 0.2Pa, and can also be set according to actual needs, which is not specifically limited in the embodiments of the present invention.

[0048] Exemplarily, the sputtering time of the Cr target or Ti target can be 25 minutes, 26 minutes, 27 minutes, 28 minutes, 29 minutes, 30 minutes, 31 minutes, 32 minutes, 33 minutes, 34 minutes, 35 minutes, 36 minutes, 37 minutes, 38 minutes, 39 minutes or 40 minutes, and can also be set according to actual needs, which is not specifically limited in the embodiments of the present invention.

[0049] As a preferred solution, the thickness of the metal transition layer is 10 to 15 nm.

[0050] Specifically, in combination with the above embodiment, the thickness of the metal transition layer deposited on the surface of the circuit board substrate is 10 nm to 15 nm.

[0051] Exemplarily, the thickness of the metal transition layer may be 10 nm, 11 nm, 12 nm, 13 nm, 14 nm or 15 nm, and may also be set according to actual needs, which is not specifically limited in the embodiment of the present invention.

[0052] In another preferred embodiment, depositing a conductive layer on the surface of the metal transition layer specifically includes:

[0053] The vacuum degree in the vacuum chamber is maintained at 0.1-0.3 Pa, and copper target sputtering is started for 20-30 minutes to complete copper plating, so as to deposit a conductive layer on the surface of the metal transition layer; wherein the conductive layer is a copper foil layer, the copper plating power is 9-10 kW, and the ion bombardment current is 20-25 A.

[0054] Specifically, in combination with the above embodiments, when a conductive layer is deposited on the surface of the metal transition layer, the vacuum degree in the vacuum chamber can be maintained at 0.1Pa~0.3Pa, and then the copper target sputtering is started for 20min~30min to complete copper plating, so as to deposit a conductive layer on the surface of the metal transition layer. Correspondingly, the conductive layer is a copper foil layer. During the copper foil plating process, the power is 9kW~10kW, and the ion bombardment current is 20A~25A.

[0055] Exemplarily, the vacuum degree in the vacuum chamber may be 0.1 Pa, 0.2 Pa or 0.3 Pa, and may also be set according to actual needs, which is not specifically limited in the embodiment of the present invention.

[0056] Exemplarily, the copper target sputtering time can be 20 minutes, 21 minutes, 22 minutes, 23 minutes, 24 minutes, 25 minutes, 26 minutes, 27 minutes, 28 minutes, 29 minutes or 30 minutes, and can also be set according to actual needs, which is not specifically limited in the embodiments of the present invention.

[0057] Exemplarily, the value of the copper plating power can be 9kW, 9.1kW, 9.2kW, 9.3kW, 9.4kW, 9.5kW, 9.6kW, 9.7kW, 9.8kW, 9.9kW or 10kW, and can also be set according to actual needs, which is not specifically limited in the embodiments of the present invention.

[0058] Exemplarily, the value of the ion bombardment current may be 20A, 21A, 22A, 23A, 24A or 25A, and may also be set according to actual needs, which is not specifically limited in the embodiment of the present invention.

[0059] As a preferred solution, the thickness of the conductive layer is 20 nm.

[0060] Specifically, in combination with the above embodiment, the thickness of the conductive layer deposited on the surface of the metal transition layer is 20 nm. It can be seen that by changing the traditional laying method of the conductive layer, the thickness of the conductive layer can reach several nanometers, thereby meeting market demand.

[0061] In yet another preferred embodiment, the gas used for ion etching is a mixed gas of carbon tetrafluoride and oxygen, and the ratio of carbon tetrafluoride to oxygen is 8:2.

[0062] Specifically, in combination with the above embodiments, when the conductive layer on the circuit board substrate that is not covered by the photosensitive material is etched by an ion etching method, the gas used is a mixture of carbon tetrafluoride (CF4) and oxygen (O2), and in the mixture, the ratio between CF4 and O2 is 8:2.

[0063] As a preferred solution, the flow rate of the mixed gas is 800-1000 sccm, the chamber temperature is 20-25° C., the chamber pressure is 20-25 mtorr, the source power is 200-250 W, and the bias power is 150 W.

[0064] Specifically, in combination with the above embodiments, in the actual process of etching the conductive layer on the circuit board substrate that is not covered by the photosensitive material, the ion etching parameters include: the flow rate of the mixed gas (i.e., CF4 and O2 mixed gas) introduced into the reaction chamber is 800sccm~1000sccm, the chamber temperature is 20℃~25℃, the chamber pressure is 20mtorr~25mtorr, the source power is 200W~250W, and the bias power is 150W.

[0065] Exemplarily, the flow rate of the mixed gas can be 800sccm, 810sccm, 820sccm, 830sccm, 840sccm, 850sccm, 860sccm, 870sccm, 880sccm, 890sccm, 900sccm, 910sccm, 920sccm, 930sccm, 940sccm, 950sccm, 960sccm, 970sccm, 980sccm, 990sccm or 1000sccm, and can also be set according to actual needs, which is not specifically limited in the embodiments of the present invention.

[0066] Exemplarily, the chamber temperature may be 20° C., 21° C., 22° C., 23° C., 24° C. or 25° C., and may also be set according to actual needs, which is not specifically limited in the embodiment of the present invention.

[0067] Exemplarily, the chamber pressure may be 20 mtorr, 21 mtorr, 22 mtorr, 23 mtorr, 24 mtorr or 25 mtorr, and may also be set according to actual needs, which is not specifically limited in the embodiment of the present invention.

[0068] Exemplarily, the source power may be 200 W, 205 W, 210 W, 215 W, 220 W, 225 W, 230 W, 235 W, 240 W, 245 W or 250 W, and may also be set according to actual needs, which is not specifically limited in the embodiments of the present invention.

[0069] As a preferred solution, the etching time of ion etching is 30 to 40 minutes.

[0070] Specifically, in combination with the above embodiment, the ion etching parameters also include: the etching time is 30 minutes to 40 minutes.

[0071] Exemplarily, the etching time can be 30 minutes, 31 minutes, 32 minutes, 33 minutes, 34 minutes, 35 minutes, 36 minutes, 37 minutes, 38 minutes, 39 minutes or 40 minutes, and can also be set according to actual needs, which is not specifically limited in the embodiment of the present invention.

[0072] In another preferred embodiment, the stripping treatment of the circuit board substrate specifically includes:

[0073] Soak the circuit board substrate in a 6% to 10% sodium hydroxide solution for 30 minutes;

[0074] The immersed circuit board substrate is cleaned with deionized water.

[0075] Specifically, in combination with the above embodiment, when the circuit board substrate is stripped, the circuit board substrate can be first soaked in a sodium hydroxide solution with a concentration of 6% to 10%, and after soaking for 30 minutes, the soaked circuit board substrate is cleaned with deionized water.

[0076] Exemplarily, the concentration of the sodium hydroxide solution may be 6%, 7%, 8%, 9% or 10%, and may also be set according to actual needs, which is not specifically limited in the embodiment of the present invention.

[0077] In combination with all the above embodiments, the implementation process of the present solution is described below through the first specific embodiment, including: (1) using deionized water to rinse the circuit board substrate, and after cleaning for 30 minutes, using an N2 gun to blow dry the cleaned circuit board substrate; (2) placing the circuit board substrate in a vacuum chamber, maintaining the vacuum degree in the vacuum chamber at 0.1 Pa, turning on the magnetron sputtering power supply, conducting current to the magnetron sputtering cathode of the magnetron sputtering target, applying a DC power supply power greater than 300 W to the magnetron sputtering target, and applying a pulse bias voltage greater than 150 V to the circuit board substrate, starting the magnetron sputtering target to sputter 2 5min, so as to deposit a metal transition layer on the surface of the circuit board substrate; wherein the magnetron sputtering target is a Cr target or a Ti target, and the thickness of the metal transition layer is 10nm; (3) the vacuum degree in the vacuum chamber is maintained at 0.1Pa, and the copper target sputtering is started for 20min to complete copper plating, so as to deposit a conductive layer on the surface of the metal transition layer, and the conductive layer is a copper foil layer; wherein, during the copper foil plating process, the power is 9kW, the ion bombardment current is 20A, and the thickness of the conductive layer is 20nm; (4) a photosensitive material is pasted on the surface of the conductive layer, and the circuit board substrate is exposed using a mask with a pattern , developing treatment to form a circuit image on the circuit board substrate, and then placing the circuit board substrate in a cleaning solution for cleaning treatment to wash away the part other than the circuit image, so that two parts covered by the photosensitive material and not covered by the photosensitive material are formed on the surface of the conductive layer; (5) using an ion etching method to etch the conductive layer not covered by the photosensitive material on the circuit board substrate, the conductive layer not covered by the photosensitive material is bombarded away, and the conductive layer covered by the photosensitive material is retained, thereby forming a conductive circuit on the circuit board substrate; wherein the gas used for ion etching is a mixed gas of CF4 and O2, and The ratio of CF4 and O2 is 8:2, and the ion etching parameters include: the flow rate of the mixed gas introduced into the reaction chamber is 800sccm, the chamber temperature is 20°C, the chamber pressure is 20mtorr, the source power is 200W, the bias power is 150W, and the etching time is 30min; (6) the etched circuit board substrate is placed in a 6% sodium hydroxide solution for immersion, and after immersion for 30min, the immersed circuit board substrate is cleaned with deionized water to remove the photosensitive material remaining on the circuit board substrate after etching, thereby obtaining a circuit board that meets the miniaturization requirements of the equipment.

[0078] In combination with all the above embodiments, the implementation process of the present solution is described below through a second specific embodiment, including: (1) using deionized water to rinse the circuit board substrate, and after cleaning for 30 minutes, using an N2 gun to blow dry the cleaned circuit board substrate; (2) placing the circuit board substrate in a vacuum chamber, maintaining the vacuum degree in the vacuum chamber at 0.15 Pa, turning on the magnetron sputtering power supply, conducting current to the magnetron sputtering cathode of the magnetron sputtering target, applying a DC power supply power greater than 300 W to the magnetron sputtering target, and applying a pulse bias voltage greater than 150 V to the circuit board substrate, starting the magnetron sputtering target to sputter for 30 minutes. 0min, so as to deposit a metal transition layer on the surface of the circuit board substrate; wherein the magnetron sputtering target is a Cr target or a Ti target, and the thickness of the metal transition layer is 12nm; (3) the vacuum degree in the vacuum chamber is maintained at 0.2Pa, and the copper target sputtering is started for 25min to complete copper plating, so as to deposit a conductive layer on the surface of the metal transition layer, and the conductive layer is a copper foil layer; wherein, during the copper foil plating process, the power is 9.5kW, the ion bombardment current is 22A, and the thickness of the conductive layer is 20nm; (4) a photosensitive material is pasted on the surface of the conductive layer, and the circuit board substrate is exposed using a mask with a pattern (5) using an ion etching method to etch the conductive layer on the circuit board substrate that is not covered by the photosensitive material, so that the conductive layer not covered by the photosensitive material is bombarded away and the conductive layer covered by the photosensitive material is retained, thereby forming a conductive circuit on the circuit board substrate; wherein the gas used for ion etching is a mixed gas of CF4 and O2, and The ratio of CF4 to O2 is 8:2, and the ion etching parameters include: the flow rate of the mixed gas introduced into the reaction chamber is 900 sccm, the chamber temperature is 22°C, the chamber pressure is 23 mtorr, the source power is 225W, the bias power is 150W, and the etching time is 35min; (6) the etched circuit board substrate is placed in an 8% sodium hydroxide solution for immersion, and after immersion for 30 minutes, the immersed circuit board substrate is cleaned with deionized water to remove the photosensitive material remaining on the circuit board substrate after etching, thereby obtaining a circuit board that meets the miniaturization requirements of the equipment.

[0079] In combination with all the above embodiments, the implementation process of the present solution is described below through a third specific embodiment, including: (1) using deionized water to rinse the circuit board substrate, and after cleaning for 30 minutes, using an N2 gun to blow dry the cleaned circuit board substrate; (2) placing the circuit board substrate in a vacuum chamber, maintaining the vacuum degree in the vacuum chamber at 0.2 Pa, turning on the magnetron sputtering power supply, conducting current to the magnetron sputtering cathode of the magnetron sputtering target, applying a DC power supply power greater than 300 W to the magnetron sputtering target, and applying a pulse bias voltage greater than 150 V to the circuit board substrate, starting the magnetron sputtering target to sputter for 40 minutes. min, so as to deposit a metal transition layer on the surface of the circuit board substrate; wherein the magnetron sputtering target is a Cr target or a Ti target, and the thickness of the metal transition layer is 15nm; (3) the vacuum degree in the vacuum chamber is maintained at 0.3Pa, and the copper target sputtering is started for 30min to complete copper plating, so as to deposit a conductive layer on the surface of the metal transition layer, and the conductive layer is a copper foil layer; wherein, during the copper foil plating process, the power is 10kW, the ion bombardment current is 25A, and the thickness of the conductive layer is 20nm; (4) a photosensitive material is pasted on the surface of the conductive layer, and the circuit board substrate is exposed using a mask with a pattern, (5) using an ion etching method to etch the conductive layer not covered by the photosensitive material on the circuit board substrate, the conductive layer not covered by the photosensitive material is bombarded away, and the conductive layer covered by the photosensitive material is retained, thereby forming a conductive circuit on the circuit board substrate; wherein the gas used for ion etching is a mixed gas of CF4 and O2, and CF The ratio of O2 to 4 is 8:2, and the ion etching parameters include: the flow rate of the mixed gas introduced into the reaction chamber is 1000 sccm, the chamber temperature is 25°C, the chamber pressure is 25 mtorr, the source power is 250 W, the bias power is 150 W, and the etching time is 40 min; (6) the etched circuit board substrate is placed in a 10% sodium hydroxide solution and soaked for 30 minutes, and then the soaked circuit board substrate is cleaned with deionized water to remove the photosensitive material remaining on the circuit board substrate after etching, thereby obtaining a circuit board that meets the miniaturization requirements of the equipment.

[0080] In summary, the method for preparing a circuit board provided by the embodiment of the present invention is as follows: first, the circuit board substrate is cleaned and dried; then, a metal transition layer is deposited on the surface of the circuit board substrate, and a conductive layer is deposited on the surface of the metal transition layer; then, a photosensitive material is pasted on the surface of the conductive layer, and the circuit board substrate is exposed, developed and cleaned using a mask with a pattern; then, the uncovered conductive layer on the circuit board substrate is etched using ion etching to form a conductive circuit on the circuit board substrate; finally, the circuit board substrate is stripped to remove the remaining photosensitive material on the circuit board substrate. The embodiment of the present invention can obtain a conductive layer with a small thickness by changing the laying method of the conductive layer on the circuit board, so that the circuit board meets the requirements of equipment miniaturization.

[0081] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a circuit board, characterized in that: include: Clean and dry the circuit board substrate; Depositing a metal transition layer on the surface of the circuit board substrate; Depositing a conductive layer on the surface of the metal transition layer; Pasting a photosensitive material on the surface of the conductive layer, and using a mask with a pattern to expose, develop and clean the circuit board substrate; Etching the uncovered conductive layer on the circuit board substrate by ion etching to form a conductive circuit on the circuit board substrate; The circuit board substrate is subjected to a film stripping process to remove the remaining photosensitive material on the circuit board substrate.

2. The method for preparing a circuit board according to claim 1, characterized in that: The cleaning and drying of the circuit board substrate specifically includes: Use deionized water to clean the circuit board substrate for 30 minutes; Use a nitrogen gun to dry the cleaned circuit board substrate.

3. The method for preparing a circuit board according to claim 1, characterized in that: The step of depositing a metal transition layer on the surface of the circuit board substrate specifically includes: Place the circuit board substrate in a vacuum chamber and maintain the vacuum degree at 0.1-0.2 Pa; Apply a power greater than 300W to the magnetron sputtering target, apply a bias voltage greater than 150V to the circuit board substrate, start the magnetron sputtering target to sputter for 25 to 40 minutes, so as to deposit a metal transition layer on the surface of the circuit board substrate; wherein the magnetron sputtering target is a chromium target or a titanium target.

4. The method for preparing a circuit board according to claim 3, characterized in that: The thickness of the metal transition layer is 10-15 nm.

5. The method for preparing a circuit board according to claim 1, characterized in that: The step of depositing a conductive layer on the surface of the metal transition layer specifically includes: The vacuum degree in the vacuum chamber is maintained at 0.1-0.3 Pa, and copper target sputtering is started for 20-30 minutes to complete copper plating, so as to deposit a conductive layer on the surface of the metal transition layer; wherein the conductive layer is a copper foil layer, the copper plating power is 9-10 kW, and the ion bombardment current is 20-25 A.

6. The method for preparing a circuit board according to claim 5, characterized in that: The thickness of the conductive layer is 20 nm.

7. The method for preparing a circuit board according to claim 1, characterized in that: The gas used for ion etching is a mixed gas of carbon tetrafluoride and oxygen, and the ratio of carbon tetrafluoride to oxygen is 8:

2.

8. The method for preparing a circuit board according to claim 7, characterized in that: The flow rate of the mixed gas is 800-1000 sccm, the chamber temperature is 20-25° C., the chamber pressure is 20-25 mtorr, the source power is 200-250 W, and the bias power is 150 W.

9. The method for preparing a circuit board according to claim 8, characterized in that: The etching time of ion etching is 30 to 40 minutes.

10. The method for preparing a circuit board according to claim 1, characterized in that: The stripping treatment of the circuit board substrate specifically includes: Soak the circuit board substrate in a 6% to 10% sodium hydroxide solution for 30 minutes; Deionized water is used to clean the immersed circuit board substrate.

Images