Manufacturing method of circuit board for optical fiber semiconductor laser

Abstract

The invention discloses a manufacturing method of a circuit board for an optical fiber semiconductor laser. The manufacturing method comprises the following steps of S1, manufacturing a working board, wherein a copper substrate and a copper foil are hot-pressed together through a PP adhesive film; s2, manufacturing a circuit pattern by adopting a negative film process; the circuit pattern comprises a plurality of circuit board manufacturing areas, and each circuit board manufacturing area is internally provided with two copper foil functional blocks which are arranged at an interval; s3, the PP adhesive film exposed in the area between the two copper foil functional blocks in each circuit board manufacturing area is milled off through laser, and the copper substrate is exposed; s4, laser is used for cutting the inner groove to obtain a plurality of circuit board semi-finished products, and non-cut parts of each row of circuit board semi-finished products are reserved; and S5, carrying out nickel-palladium-gold immersion process treatment on the working board to obtain a finished circuit board. S6, connecting each row of circuit board semi-finished products into a string by using an adhesive tape; and S7, cutting the uncut part by using laser to obtain a single separated circuit board finished product. Batch manufacturing can be achieved, the production efficiency is improved, and the cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit board production, and in particular to a method for manufacturing a circuit board for an optical fiber semiconductor laser. Background Art

[0002] Circuit boards for fiber semiconductor lasers, such as Figure 1 and Figure 2 As shown, the copper block is in the shape of a Chinese character "concave", and has conductive functional parts (such as Figure 1 and Figure 2 A, B, and C in the figure indicate the parts respectively), wherein the two conductive functional parts corresponding to the live wire and the neutral wire are arranged in the upper layer of the copper block, and the conductive functional part corresponding to the ground wire is arranged in the lower layer of the copper block, and an insulating layer (such as Figure 1 and Figure 2 The circuit board has a unique structure and a small size, with a thickness of more than 3 mm. It is difficult to etch and difficult to mass produce using traditional PCB manufacturing processes, resulting in low production efficiency and high cost. Summary of the invention

[0003] The purpose of the present invention is to provide a method for manufacturing a circuit board for an optical fiber semiconductor laser, which can realize batch manufacturing, improve production efficiency and reduce costs.

[0004] In order to achieve the above object, the present invention provides a method for manufacturing a circuit board for an optical fiber semiconductor laser, which comprises the following steps:

[0005] S1. Make the working board: heat press the copper substrate and copper foil together through PP adhesive film;

[0006] S2. A circuit pattern is produced by a negative film process; wherein the circuit pattern comprises a plurality of circuit board production areas, the plurality of circuit board production areas are arranged in a rectangular array on a work plate, and each of the circuit board production areas has two copper foil functional blocks spaced apart from each other;

[0007] S3. Using laser milling to remove the PP film exposed in the area between the two copper foil functional blocks in each circuit board production area, exposing the copper substrate;

[0008] S4. According to the desired circuit board design shape, the inner groove is cut by laser to obtain multiple connected circuit board semi-finished products. In each column of circuit board semi-finished products, the uncut parts are retained between two adjacent circuit board semi-finished products and between the circuit board semi-finished products and the edge of the working board;

[0009] S5. The working board after step S4 is subjected to nickel-palladium-gold immersion process to obtain a plurality of connected circuit board products;

[0010] S6. Use tape to connect each row of semi-finished circuit boards into a string, and stick the tape to the edges of the boards on both sides of the work board;

[0011] S7. Using the laser cutting step S4 to retain the uncut portion, a single separated circuit board product is obtained;

[0012] S8. Remove the tape and the production is completed.

[0013] As a preferred embodiment of the present invention, in step S1, the thickness of the PP film is 0.05 mm, the thickness of the copper foil is 0.5 mm, and the thickness of the copper substrate is 2.5 mm.

[0014] As a preferred embodiment of the present invention, the specific steps of step S2 are:

[0015] S21. Drilling tool holes on the edge of the work plate;

[0016] S22. Grind the copper layers on the upper and lower surfaces of the working board, remove debris and oxide layers from the board surface, and level the copper surface;

[0017] S23. A photosensitive dry film is affixed to the upper and lower surfaces of the work plate;

[0018] S24. After the circuit film and the work plate with the dry film are aligned, they are placed in an exposure machine for exposure. By using the "photographic" principle, the circuit on the circuit film is transferred to the surface of one side of the copper foil, and the unexposed dry film part is developed by a developing solution, thereby exposing the copper foil not protected by the dry film;

[0019] S25. Using an etching solution to remove the exposed copper foil, exposing the PP film, and leaving the copper foil protected by the dry film, that is, the desired circuit pattern;

[0020] S26. Stripping the dry film of the non-circuit pattern of the working board to complete the circuit pattern production.

[0021] As a preferred embodiment of the present invention, in the finished circuit board, a PP film with a width of 0.3 mm is retained around the copper foil functional block.

[0022] As a preferred embodiment of the present invention, the following steps are also included between step S3 and step S4: respectively engraving laser characters on a copper foil functional block in each circuit board production area, and the laser characters in each circuit board production area are unique identification characters.

[0023] As a preferred embodiment of the present invention, the nickel thickness of the finished circuit board after the processing in step S5 is 4 μm, the palladium thickness is 0.1 μm, and the gold thickness is not less than 0.2 μm.

[0024] As a preferred embodiment of the present invention, in step S6, the adhesive tape is a non-stick adhesive tape.

[0025] As a preferred embodiment of the present invention, in step S6, the width of the tape is smaller than the width of the finished circuit board.

[0026] The method for manufacturing a circuit board for an optical fiber semiconductor laser provided by the present invention has the following beneficial effects compared with the prior art:

[0027] The method for manufacturing a circuit board for an optical fiber semiconductor laser of the present invention combines a variety of key technologies in modern circuit board manufacturing, including heat pressing, negative film processing, laser cutting processing and gold deposition processing, and can realize batch manufacturing of circuit boards for optical fiber semiconductor lasers, improve production efficiency, reduce costs, and ensure the quality and performance of the circuit boards. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the front view of the circuit board for the optical fiber semiconductor laser;

[0029] Figure 2 It is Figure 1 A cross-sectional view taken along the EE direction of the structure shown;

[0030] Figure 3 It is a structural schematic diagram after manufacturing a circuit pattern in the method for manufacturing a circuit board for an optical fiber semiconductor laser provided by an embodiment of the present invention;

[0031] Figure 4 It is a schematic diagram of the distribution of laser milling areas in the method for manufacturing a circuit board for an optical fiber semiconductor laser provided by an embodiment of the present invention;

[0032] Figure 5 It is a structural schematic diagram of laser cutting inner grooves and retaining uncut parts in the method for manufacturing a circuit board for an optical fiber semiconductor laser provided by an embodiment of the present invention;

[0033] Figure 6 It is a structural schematic diagram of connecting each row of semi-finished circuit boards into a string by using adhesive tape in the method for manufacturing a circuit board for an optical fiber semiconductor laser provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0035] like Figures 1 to 6 As shown, a method for manufacturing a circuit board for an optical fiber semiconductor laser provided by an embodiment of the present invention comprises the following steps:

[0036] S1. Making a working board: hot press the copper substrate 1 and the copper foil 2 together through the PP adhesive film 3; wherein the thickness of the PP adhesive film 3 is 0.05 mm, the thickness of the copper foil 2 is 0.5 mm, and the thickness of the copper substrate 1 is 2.5 mm. This step involves the PP hot pressing hot melting method, which heats the adhesive film for hot melting bonding to achieve a high-strength, long-lasting, stable, immersion-resistant, acid- and alkali-resistant bonding effect.

[0037] S2. Use negative film technology to make circuit graphics (such as Figure 3 As shown); wherein, the circuit pattern includes a plurality of circuit board production areas, and the plurality of circuit board production areas are arranged in a rectangular array on the working board, and each of the circuit board production areas has two separated copper foil functional blocks 21 (i.e., two conductive functional parts A and B respectively connected to the live wire and the neutral wire in the technical background);

[0038] The specific steps of step S2 are:

[0039] S21. Drill a tool hole 4 on the edge of the work plate; the tool hole plays a role in positioning the work plate in subsequent processes;

[0040] S22. Grind the copper layers on the upper and lower surfaces of the working board, remove debris and oxide layers from the board surface, and level the copper surface;

[0041] S23. A photosensitive dry film is affixed to the upper and lower surfaces of the work plate;

[0042] S24. After the circuit film and the work plate with the dry film are aligned, they are placed in an exposure machine for exposure. By using the "photographic" principle, the circuit on the circuit film is transferred to the surface of one side of the copper foil 2, and the unexposed dry film part is developed by a developing solution, so that the copper foil 2 not protected by the dry film is exposed;

[0043] S25. Use an etching solution (usually an acidic solution) to remove the exposed copper foil 2, exposing the PP film 3, and leaving the copper foil 2 protected by the dry film, that is, the desired circuit pattern;

[0044] S26. Stripping the dry film of the non-circuit pattern of the working board to complete the circuit pattern production.

[0045] S3. Use laser milling to remove the area between two copper foil functional blocks in each circuit board production area (such as Figure 4 The PP film 3 (the part indicated by F in the figure) exposes the copper substrate 1 (i.e., the conductive functional part C corresponding to the ground wire in the technical background);

[0046] The specific steps of step S3 are:

[0047] S31. First, according to the design drawing of the circuit board, use CAD software to design the path where the PP film 3 needs to be milled (such as Figure 4 Then, the designed path is imported into the control system of the laser milling machine and programmed to ensure that the laser milling machine can perform accurate milling according to the predetermined path;

[0048] S32. According to the material properties and milling requirements of the PP film 3, set the parameters of the laser milling machine, including laser power, cutting speed, focal length, etc.;

[0049] S33. Start the laser milling machine, and the laser beam mills on the working plate according to a preset path; the laser beam removes the material in the designated area by evaporation or melting, thereby exposing the copper substrate 1.

[0050] S4. According to the required circuit board design shape, use laser to cut the inner groove (such as Figure 5 A plurality of connected semi-finished circuit boards are obtained, and in each row of semi-finished circuit boards, uncut portions are retained between two adjacent semi-finished circuit boards and between the semi-finished circuit boards and the edge of the working board (e.g. Figure 5 The part indicated by H in the figure);

[0051] The specific steps of step S4 are:

[0052] S41. First, the path for inner groove cutting needs to be designed using CAD software according to the design drawings of the circuit board; then, the designed path is imported into the control system of the laser cutting machine and programmed to ensure that the laser cutting machine can accurately cut according to the predetermined path;

[0053] S42. According to the characteristics of the material (such as the copper substrate 1, the PP film 3, etc.) and the cutting requirements, set the parameters of the laser cutting machine, including laser power, cutting speed, focal length, etc.;

[0054] S43. Start the laser cutting machine, and the laser beam cuts on the work plate according to a preset path; the laser beam removes the material in the designated area by evaporation or melting to form an inner groove.

[0055] During the cutting process, it is necessary to keep the connection parts between each row of semi-finished circuit boards, as well as the connection parts between the semi-finished circuit boards and the edges of the working boards. These uncut parts ensure that the semi-finished circuit boards can still be connected in subsequent processes, such as nickel-palladium-gold treatment and tape application, so as to facilitate batch processing.

[0056] S5. The working board after step S4 is subjected to nickel-palladium-gold immersion process to obtain a plurality of connected circuit board products;

[0057] It should be noted that the process of nickel-palladium-gold plating generally includes degreasing, micro-etching, pickling, pre-dip, palladium activation, chemical nickel (reduction), chemical palladium (reduction) and chemical gold (replacement); the nickel-palladium-gold plating process eventually forms a stable nickel-palladium alloy layer on the surface of the copper layer. This alloy layer has excellent wear resistance, corrosion resistance and anti-discoloration properties, and can effectively protect the metal surface from environmental influences. In addition, the surface treated by the nickel-palladium-gold plating process is very smooth. This flatness can improve conductivity and signal transmission effects, while reducing surface reflection and scattering, which helps to improve the performance and reliability of electronic products.

[0058] In this embodiment, the nickel thickness of the finished circuit board after the processing in step S5 is 4 μm, the palladium thickness is 0.1 μm, and the gold thickness is not less than 0.2 μm.

[0059] S6. Use tape 5 to connect each row of semi-finished circuit boards into a string, and stick the tape 5 to the edges of the boards on both sides of the working board, such as Figure 6 As shown; wherein, the tape 5 is preferably a non-stick tape to prevent adhesive residue from being left on the semi-finished circuit board product when the tape 5 is subsequently torn off; the width of the tape 5 is smaller than the width of the finished circuit board product to avoid the tape blocking the uncut portion retained in step S4.

[0060] S7. Using the laser cutting step S4 to retain the uncut portion, a single separated circuit board product is obtained;

[0061] S8. Remove the tape and the production is completed.

[0062] Exemplarily, in the finished circuit board, a PP adhesive film 3 with a width of 0.3 mm is retained around the copper foil functional block to ensure insulation between the two copper foil functional blocks and the copper substrate 1 .

[0063] Exemplarily, the following step is also included between step S3 and step S4: respectively engraving laser characters on a copper foil functional block in each circuit board production area, and the laser characters in each circuit board production area are unique identification characters to facilitate subsequent identification and tracing.

[0064] In summary, the method for manufacturing a circuit board for an optical fiber semiconductor laser provided by the present invention combines multiple key technologies in modern circuit board manufacturing, including thermal pressing, negative film process, laser cutting processing and gold deposition process, and can realize batch manufacturing of circuit boards for optical fiber semiconductor lasers, improve production efficiency, reduce costs, and ensure the quality and performance of the circuit boards.

[0065] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0066] Although embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for manufacturing a circuit board for an optical fiber semiconductor laser, characterized in that: The following steps are involved: S1. Make the working board: heat press the copper substrate and copper foil together through PP adhesive film; S2. A circuit pattern is produced by a negative film process; wherein the circuit pattern comprises a plurality of circuit board production areas, the plurality of circuit board production areas are arranged in a rectangular array on a work plate, and each of the circuit board production areas has two copper foil functional blocks spaced apart from each other; S3. Using laser milling to remove the PP film exposed in the area between the two copper foil functional blocks in each circuit board production area, exposing the copper substrate; S4. According to the desired circuit board design shape, the inner groove is cut by laser to obtain multiple connected circuit board semi-finished products. In each column of circuit board semi-finished products, the uncut parts are retained between two adjacent circuit board semi-finished products and between the circuit board semi-finished products and the edge of the working board; S5. The working board after step S4 is subjected to nickel-palladium-gold immersion process to obtain a plurality of connected circuit board products; S6. Use tape to connect each row of semi-finished circuit boards into a string, and stick the tape to the edges of the boards on both sides of the work board; S7. Using the laser cutting step S4 to retain the uncut portion, a single separated circuit board product is obtained; S8. Remove the tape and the production is completed.

2. The method for manufacturing a circuit board for an optical fiber semiconductor laser according to claim 1, characterized in that: In the step S1, the thickness of the PP film is 0.05 mm, the thickness of the copper foil is 0.5 mm, and the thickness of the copper substrate is 2.5 mm.

3. The method for manufacturing a circuit board for an optical fiber semiconductor laser according to claim 1, characterized in that: The specific steps of step S2 are: S21. Drilling tool holes on the edge of the work plate; S22. Grind the copper layers on the upper and lower surfaces of the working board, remove debris and oxide layers from the board surface, and level the copper surface; S23. A photosensitive dry film is affixed to the upper and lower surfaces of the work plate; S24. After the circuit film and the work plate with the dry film are aligned, they are placed in an exposure machine for exposure. By using the "photographic" principle, the circuit on the circuit film is transferred to the surface of one side of the copper foil, and the unexposed dry film part is developed by a developing solution, thereby exposing the copper foil not protected by the dry film; S25. Using an etching solution to remove the exposed copper foil, exposing the PP film, and leaving the copper foil protected by the dry film, that is, the desired circuit pattern; S26. Stripping the dry film of the non-circuit pattern of the working board to complete the circuit pattern production.

4. The method for manufacturing a circuit board for an optical fiber semiconductor laser according to claim 1, characterized in that: In the finished circuit board, a PP film with a width of 0.3 mm is retained around the copper foil functional block.

5. The method for manufacturing a circuit board for an optical fiber semiconductor laser according to claim 1, characterized in that: The following step is also included between step S3 and step S4: respectively engraving laser characters on a copper foil functional block in each circuit board production area, and the laser characters in each circuit board production area are unique identification characters.

6. The method for manufacturing a circuit board for an optical fiber semiconductor laser according to claim 1, characterized in that: The finished circuit board after the processing in step S5 has a nickel thickness of 4 μm, a palladium thickness of 0.1 μm, and a gold thickness of not less than 0.2 μm.

7. The method for manufacturing a circuit board for an optical fiber semiconductor laser according to claim 1, characterized in that: In the step S6, the tape is a non-stick tape.

8. The method for manufacturing a circuit board for an optical fiber semiconductor laser according to claim 1, characterized in that: In the step S6, the width of the tape is smaller than the width of the finished circuit board.

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