阅读说明：本技术 一种pcb单层板以及pcb多层板的制备方法 (Preparation method of single-layer PCB and multi-layer PCB ) 是由 孙明 刘权锋 庄文荣 卢敬权 于 2019-10-12 设计创作，主要内容包括：本发明提供一种PCB单层板以及PCB多层板制备方法,所述PCB单层板的制备方法包括1)提供一基板；2)于所述基板的上表面以及下表面覆压铜膜,形成覆铜板；3)于所述覆铜板表面覆压抗蚀干膜；4)通过曝光、显影工艺,形成图案化的抗蚀干膜；5)采用等离子体刻蚀工艺,以所述图案化的抗蚀干膜为掩膜,刻蚀所述铜膜；6)去除所述抗蚀干膜,露出线路图形,完成线路图案的制作。基于上述技术方案,本发明通过刻蚀工艺的改进,得到了一种高精度的PCB单层板与PCB多层板。(The invention provides a method for preparing a single-layer PCB (printed circuit board) and a PCB multi-layer board, wherein the method for preparing the single-layer PCB comprises the following steps of 1) providing a substrate; 2) covering and pressing copper films on the upper surface and the lower surface of the substrate to form a copper-clad plate; 3) laminating a corrosion-resistant dry film on the surface of the copper-clad plate; 4) forming a patterned dry film resist by exposure and development processes; 5) etching the copper film by adopting a plasma etching process and taking the patterned corrosion-resistant dry film as a mask; 6) and removing the corrosion-resistant dry film to expose the circuit pattern, thereby finishing the manufacture of the circuit pattern. Based on the technical scheme, the high-precision single-layer PCB and the high-precision multi-layer PCB are obtained by improving the etching process.)

1. A method for preparing a single-layer PCB is characterized by at least comprising the following steps:

1) providing a substrate;

2) simultaneously laminating copper films on the upper surface and the lower surface of the substrate to form a copper-clad plate;

3) laminating a corrosion-resistant dry film on the surface of the copper-clad plate;

4) forming a patterned dry film resist by exposure and development processes;

5) etching the copper film by adopting a plasma etching process and taking the patterned corrosion-resistant dry film as a mask;

6) and removing the corrosion-resistant dry film to expose the circuit pattern, thereby finishing the manufacture of the circuit pattern.

2. The method for manufacturing a single-layer PCB as recited in claim 1, wherein the step 3) further comprises the step of cleaning the surface of the cover plate before the dry film resist is coated on the surface of the copper clad plate.

3. The method for manufacturing a single-layer PCB as recited in claim 1, wherein in the step 3), a dry film resist is laminated on the surface of the copper clad laminate by using a hot pressing method.

4. The method for preparing the single-layer PCB as recited in claim 1, wherein in the step 5), the process parameters of the plasma etching process comprise: the process gas comprises Cl₂、BCl₃And Ar, the source radio frequency power is 200W-1500W, the bias radio frequency power is 100W-300W, and the process time is 40 s-60 min.

5. The method for preparing a single-layer PCB board as claimed in claim 1, wherein in step 1), the material of the substrate includes one or a combination of two of organic material and inorganic material, the organic material includes phenolic resin, glass fiber, epoxy resin or polyimide, and the inorganic material includes aluminum, copper and ceramic.

6. The method for manufacturing a single-layer PCB as recited in any one of claims 1 to 5, wherein the steps 2) to 6) are respectively performed on the upper surface and/or the lower surface of the substrate.

7. The method for manufacturing a single-layer PCB board as claimed in any one of claims 1 to 5, wherein the method is applied to manufacture a PCB board of a Mini LED or a Micro LED.

8. The preparation method of the PCB multilayer board is characterized by at least comprising the following steps:

1) providing a multilayer wiring board which comprises two outer plates parallel to each other and an inner plate arranged between the two outer plates, wherein the multilayer wiring board is provided with a through hole penetrating through the outer plates and the inner plate;

2) sequentially forming a chemical copper plating film and a first copper plating film on the front surface and the back surface of the multilayer wiring board and the hole wall of the through hole through a chemical copper plating process and an electrolytic copper plating process;

3) forming a patterned first corrosion-resistant dry film on the surface of the first electroplated copper film on the back surface of the multilayer wiring board;

4) sequentially forming a second copper electroplating film and a copper protective film on the surface of the first copper electroplating film by continuously adopting an electroplating process by taking the patterned first corrosion-resistant dry film as a mask;

5) removing the first corrosion-resistant dry film, sequentially removing the first electroplated copper film and the chemical copper plated film on the back surface of the multilayer wiring board by using the copper protective film as a mask and adopting an etching process, and removing the copper protective film to expose a circuit pattern on the back surface of the multilayer wiring board;

6) forming a patterned second dry etching resistant film on the surface of the second electroplated copper film on the front surface of the multilayer wiring board;

7) sequentially removing the second electroplated copper film, the first electroplated copper film and the chemical copper-plated film on the front surface of the multilayer wiring board by using the second anti-corrosion dry film as a mask and adopting a plasma etching process;

8) and removing the second etching resistant dry film, and exposing the circuit pattern on the front surface of the multilayer wiring board.

9. The method for preparing a PCB multilayer board according to claim 8, wherein in step 7), the process parameters of the plasma etching comprise: the process gas comprises Cl₂、BCl₃And Ar, the source radio frequency power is 200W-1500W, the bias radio frequency power is 100W-300W, and the process time is 40 s-60 min.

10. The method for manufacturing a PCB multi-layer board according to claim 8, further comprising: in the step 2), before the steps of sequentially forming the electroless copper plating film and the first electrolytic copper plating film on the front surface and the back surface of the multilayer wiring board and the hole wall of the through hole, the steps of laminating the copper films on the front surface and the back surface of the multilayer wiring board to form the copper-clad film are performed through an electroless copper plating process and an electrolytic copper plating process, and in the step 5), the steps of sequentially removing the first electrolytic copper plating film, the electroless copper plating film and the copper-clad film on the back surface of the multilayer wiring board and the step 7) and sequentially removing the second electrolytic copper plating film, the first electrolytic copper plating film, the electroless copper plating film and the copper-clad film on the front surface of the multilayer wiring board.

11. The method for manufacturing a multilayer PCB panel according to claim 8, wherein the step 6) further comprises a step of removing the electroless copper plating film and the first and second electroplated copper films on the front surface of the multilayer wiring board and depositing a Ti/Al/Ni/Au multilayer metal thin film on the front surface of the multilayer wiring board before the step of forming a second dry etching resistant film on the surface of the second electroplated copper film on the front surface of the multilayer wiring board.

12. The method for manufacturing a PCB multi-layer board according to claim 8, wherein the patterned first dry film resist and the patterned second dry film resist are manufactured through exposure and development processes.

13. The method for manufacturing a PCB multi-layer board according to any one of claims 8 to 12, wherein the inner layer board is manufactured by the method for manufacturing a PCB single-layer board according to any one of claims 1 to 6.

14. The method for preparing the PCB multilayer board as claimed in any one of claims 8 to 12, wherein the method is applied to the preparation of the PCB of Mini LED or Micro LED.

Technical Field

The invention relates to the technical field of PCB (printed circuit board), in particular to a method for preparing a single-layer PCB and a multi-layer PCB.

Background

With the continuous improvement of indoor display application technology, currently used display application products such as projection/DLP/LCD/PDP and the like cannot completely meet the market application requirements. There are also some drawbacks in various aspects that make it impossible to break through the technological development. The LED full-color display screen overcomes the defects of the products, and becomes a first choice for indoor and outdoor large-screen display, such as occasions of command centers, outdoor advertising screens, conference centers and the like.

Generally, the LED display screen is seamlessly spliced into a large-sized display screen by a certain number of small-sized display screen modules. The manufacturing method of the small-spacing display screen module comprises the following steps: 1. discrete devices (SMDs); 2.4 in 1Mini LED (IMD); chip On Board (COB). At present, the minimum dot pitch of the LED display screen is 0.9375mm (P0.9), but the market has wide demand for the LED display screen with smaller dot pitch. The picture can be clearer due to the small dot spacing. However, when the dot pitch is smaller than 0.7mm, both the SMD method and the IMD method cannot meet the requirements, and only the COB method can manufacture an LED display screen with a smaller dot pitch.

In the current COB method, the substrate is a PCB, and the conventional PCB manufacturing process can meet the requirements of a display screen with a specification of more than P0.7, and the chip size can be as small as 04x06 mil. When the specification is smaller than P0.7, the chip size is even as small as 04x05mil or 02x04mil, and the precision of the conventional PCB manufacturing process is far from the requirement. This is because in the conventional PCB fabrication process, the pattern is formed by wet etching, and over-etching easily occurs during this process, so that the pattern accuracy is degraded.

Therefore, it is an urgent problem for those skilled in the art to improve the circuit accuracy of a single-layer board or a multi-layer board of a PCB.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention is directed to a method for manufacturing a single-layer PCB and a multi-layer PCB, so as to improve the circuit accuracy of the single-layer PCB or the multi-layer PCB.

In order to achieve the above and other related objects, the present invention provides a method for manufacturing a single-layer PCB, comprising at least the steps of:

1) providing a substrate;

2) simultaneously laminating copper films on the upper surface and the lower surface of the substrate to form a copper-clad plate;

3) laminating a corrosion-resistant dry film on the surface of the copper-clad plate;

4) forming a patterned dry film resist by exposure and development processes;

5) etching the copper film by adopting a plasma etching process and taking the patterned corrosion-resistant dry film as a mask;

6) and removing the corrosion-resistant dry film to expose the circuit pattern, thereby finishing the manufacture of the circuit pattern.

Optionally, step 3) further comprises the step of cleaning the surface of the covering board before the dry film resist is coated on the surface of the copper clad board.

Optionally, in step 3), a dry film resist is coated and pressed on the surface of the copper clad laminate by using a hot pressing method.

Optionally, in step 5), the process parameters of the plasma etching process include: the process gas comprises Cl₂、BCl₃And Ar, the source radio frequency power is 200W-1500W, the bias radio frequency power is 100W-300W, and the process time is 40 s-60 min.

Optionally, in step 1), the material of the substrate includes one or a combination of two of an organic material and an inorganic material, the organic material includes a phenolic resin, a glass fiber, an epoxy resin or a polyimide, and the inorganic material includes aluminum, copper or ceramic.

Optionally, the steps 2) to 6) are respectively executed on the upper surface and/or the lower surface of the copper-clad plate.

Optionally, the preparation method is applied to the manufacture of a PCB of a Mini LED or a Micro LED.

The invention also provides a preparation method of the PCB multilayer board, which at least comprises the following steps:

1) providing a multilayer wiring board which comprises two outer plates parallel to each other and an inner plate arranged between the two outer plates, wherein the multilayer wiring board is provided with a through hole penetrating through the outer plates and the inner plate;

2) sequentially forming a chemical copper plating film and a first copper plating film on the front surface and the back surface of the multilayer wiring board and the hole wall of the through hole through a chemical copper plating process and an electrolytic copper plating process;

3) forming a patterned first corrosion-resistant dry film on the surface of the first electroplated copper film on the back surface of the multilayer wiring board;

4) sequentially forming a second copper electroplating film and a copper protective film on the surface of the first copper electroplating film by continuously adopting an electroplating process by taking the patterned first corrosion-resistant dry film as a mask;

5) removing the first corrosion-resistant dry film, removing the chemical copper plating film and the first electroplated copper film on the back surface of the multilayer wiring board by using the copper protective film as a mask and adopting an etching process, and removing the copper protective film to expose a circuit pattern on the back surface of the multilayer wiring board;

6) forming a patterned second dry etching resistant film on the surface of the second electroplated copper film on the front surface of the multilayer wiring board;

7) sequentially removing the second electroplated copper film, the second electroplated copper film and the chemical copper-plated film on the front surface of the multilayer wiring board by using the second anti-corrosion dry film as a mask and adopting a plasma etching process;

8) and removing the second etching resistant dry film, and exposing the circuit pattern on the front surface of the multilayer wiring board.

Optionally, in step 7), the process parameters of the plasma etching process include: the process gas comprises Cl₂、BCl₃And Ar, the source radio frequency power is 200W-1500W, the bias radio frequency power is 100W-300W, and the process time is 40 s-60 min.

Optionally, the method for preparing the PCB multi-layer board further comprises: in the step 2), before the steps of sequentially forming the electroless copper plating film and the first electrolytic copper plating film on the front surface and the back surface of the multilayer wiring board and the hole wall of the through hole, the steps of laminating the copper films on the front surface and the back surface of the multilayer wiring board to form the copper-clad film are performed through an electroless copper plating process and an electrolytic copper plating process, and in the step 5), the steps of sequentially removing the first electrolytic copper plating film, the electroless copper plating film and the copper-clad film on the back surface of the multilayer wiring board and the step 7) and sequentially removing the second electrolytic copper plating film, the first electrolytic copper plating film, the electroless copper plating film and the copper-clad film on the front surface of the multilayer wiring board.

Optionally, in step 6), before the step of forming the second dry etching resist film on the surface of the second copper plating film on the front surface of the multilayer wiring board, a step of removing the electroless copper plating film on the front surface of the multilayer wiring board and the first and second copper plating films and depositing a Ti/Al/Ni/Au multilayer metal thin film is further included.

Optionally, the patterned first dry film resist and the patterned second dry film resist are prepared by exposure and development processes.

Optionally, the inner plate is prepared by the preparation method of the single-layer PCB.

Optionally, the preparation method is applied to manufacturing a PCB of a Mini LED or a Micro LED.

The invention obtains a high-precision single-layer PCB and a PCB multi-layer board by improving the etching process.

Drawings

Fig. 1 shows a flow chart of a method for manufacturing a single-layer PCB according to the present invention.

Fig. 2 to 6 are schematic structural diagrams illustrating a process of manufacturing a single-layer PCB according to an embodiment of the present invention.

Fig. 7 shows a flow chart of a method for manufacturing a PCB multi-layer board provided by the present invention.

Fig. 8 to 16 are schematic structural diagrams illustrating a PCB multi-layer board according to a second embodiment of the invention.

Fig. 17 is a schematic structural view illustrating the removal of the copper film in the fourth embodiment of the invention.

FIG. 18 is a schematic structural diagram of a Ti/Al/Ni/Au multilayer metal film deposited in the fourth embodiment of the present invention.

Fig. 19 is a schematic structural view of a PCB multi-layer board formed in the fourth embodiment of the present invention.

Description of the element reference numerals

10 copper-clad plate

11 substrate

12 copper film

13 first dry film resist

20 multilayer wiring board

21 inner plate

22 outer plate

23 through hole

24 electroless copper plating film

25 first copper electroplating film

26 first dry film resist

27 second copper electroplating film

28 copper protective film

29 second resist dry film

34 electroless copper plating film

35 first copper electroplating film

37 second copper electroplating film

39 Ti/Al/Ni/Au multilayer metal film

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

Please refer to fig. 1 to 19. It should be noted that the drawings provided in the present embodiment are only schematic and illustrate the basic idea of the present invention, and although the drawings only show the components related to the present invention and are not drawn according to the number, shape and size of the components in actual implementation, the form, quantity and proportion of the components in actual implementation may be changed arbitrarily, and the layout of the components may be more complicated.