Mini-LED packaging BT substrate and manufacturing method thereof

Abstract

The invention provides a manufacturing method of a Mini-LED packaging BT substrate, and the method comprises the following steps: S1, carrying out the processing of the surface of a BT carrier plate, and enabling the surface to form a compact light absorption film layer; s2, performing laser grooving on the BT carrier plate subjected to surface treatment; s3, electroplating and copper deposition are carried out on the BT carrier plate after slotting; s4, a circuit pattern is manufactured on the BT carrier plate after copper deposition is completed; s5, performing resistance welding processing on the BT carrier plate on which the circuit pattern is manufactured; and S6, carrying out nickel-palladium-gold treatment on the BT carrier plate subjected to resistance welding treatment, and then carrying out cleaning, cutting, fragmentation and inspection to obtain the Mini-LED packaging BT substrate. According to the manufacturing method of the Mini-LED packaging BT substrate provided by the invention, the surface of a BT carrier plate is treated, so that a compact light absorption film layer is formed on the surface of the BT carrier plate; according to the method, the undemanded area is removed through the laser, grooving of the LED packaging BT substrate is achieved, the width of the groove can be not larger than 0.1 mm, the cutting quality is improved, the grooving precision is improved, the manufacturing cost is reduced, and therefore high-precision and low-cost grooving manufacturing is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of chip packaging substrate processing, and specifically to a Mini-LED packaging BT substrate and a manufacturing method thereof. Background Art

[0002] Mini-LED has the characteristics of high resolution, high brightness, high contrast and wide color gamut, which can greatly improve the performance of LED panels. Currently, the products using Mini-LED technology on the market include large-size TVs, high-end monitors, laptops and tablets.

[0003] BT (Bismaleime de Triazine) board, full name BT resin substrate material, is a high-performance substrate material for PCB. It has high glass transition temperature (Tg), excellent dielectric properties, low thermal expansion coefficient, good mechanical characteristics and other properties, making it widely used in the increasingly popular high-density interconnection (HDI) multi-layer printed circuit boards and Mini-LED packaging substrates.

[0004] At present, in the manufacturing method of MiniLED package BT substrate, conventional grooving process is usually adopted, that is, die stamping or CNC milling cutter is used to complete the grooving. However, both die stamping and CNC milling cutter processing have low processing accuracy in the grooving process, the minimum processing spacing is too large, and the yield rate is low, which in turn affects the accuracy of post-process alignment processing, as well as the yield rate and efficiency of the packaging process. In addition, other materials need to be used in the production process to assist in processing and production, resulting in high production costs.

[0005] In view of this, it is necessary to provide a new production process to solve the above-mentioned technical problems. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention proposes a method for manufacturing a Mini-LED package BT substrate, which can improve cutting quality, improve grooving accuracy and reduce manufacturing costs.

[0007] In order to solve the above problems, the technical solution of the present invention is as follows:

[0008] A method for manufacturing a Mini-LED package BT substrate comprises the following steps:

[0009] S1. Treat the surface of the BT carrier board to form a dense light-absorbing film layer on the surface;

[0010] S2, laser grooving the surface treated BT substrate;

[0011] S3, electroplating copper on the slotted BT substrate;

[0012] S4, making circuit patterns on the BT carrier board after copper deposition;

[0013] S5, performing solder mask treatment on the BT carrier board with the completed circuit pattern;

[0014] S6. Treat the BT substrate that has been treated with solder mask with nickel-palladium-gold, and then clean, cut, slice, and inspect to obtain the Mini-LED package BT substrate.

[0015] In the present invention, the surface of the BT carrier is processed to form a dense light-absorbing film layer on its surface; then the non-required areas (copper oxide layer, BT carrier, copper, etc. at designated positions) are removed by laser to achieve grooving of the LED package BT substrate, and the groove width can reach no more than 0.1 mm.

[0016] In the present invention, the BT carrier board is surface treated to form a dense light-absorbing film layer, whose light-absorbing energy is increased, the cutting speed is fast, and ablation is not performed at the same position, thereby improving the cutting quality and reducing the burning of the BT layer by the laser, thereby avoiding the excessive roughness of the groove wall caused by the shrinkage or protrusion of the resin, thereby improving the groove accuracy and reducing the production cost, thereby realizing high-precision and low-cost groove production.

[0017] Furthermore, in step S1, the surface treatment method of the BT carrier is: oxidizing the surface of the BT carrier to form a dense oxide film on the surface, laying a light-absorbing material on the surface of the oxide film, forming a light-absorbing layer after drying, increasing the degree of light absorption, and finally browning or blackening the surface of the light-absorbing layer to form a dense light-absorbing film layer. There is no special requirement for the light-absorbing material in the present invention, and one of black paint or ink can be used.

[0018] Furthermore, the specific method of oxidizing the surface of the BT carrier to form a dense oxide film on the surface is: at 100-200° C., the BT carrier is placed in a nitrogen atmosphere, and oxygen with a volume fraction of 10%-30% is continuously introduced to form an oxide layer on the surface.

[0019] In the present invention, the oxide layer is prepared by heating and introducing oxygen to form a dense oxide film with better light absorption and corrosion resistance. A light-absorbing material is laid on the surface of the oxide film to increase the light absorption energy of the surface layer, and then browning or blackening is performed to form a dense light-absorbing film layer, thereby further improving the light absorption effect of the surface layer, which can increase the cutting speed during laser cutting, improve the cutting quality, and thus improve the performance of the BT substrate.

[0020] Furthermore, the BT carrier board is one of a BT copper-clad board, a BT aluminum-clad board, a gold-plated BT board, a silver-plated BT board or a copper-plated BT board.

[0021] In the present invention, there is no specific limitation on the BT carrier board, and a variety of BT boards can be used, such as BT copper-clad boards, BT aluminum-clad boards, gold-plated BT boards, silver-plated BT boards or copper-plated BT boards. BT copper-clad boards or copper-plated BT boards are preferred, which can save costs and have high electrical conductivity, and are suitable for Mini-LED packaging.

[0022] It should be noted that the laser used for laser grooving in the present invention is a common laser, and there is no special requirement. It can be selected from one of ultraviolet picosecond laser, solid-state laser, semiconductor laser, gas laser, excimer laser, or fiber laser. Ultraviolet picosecond laser is preferred.

[0023] Further, when the laser is an ultraviolet picosecond laser, the laser conditions are: setting the laser spot size to 10-80 μm;

[0024] In the present invention, the ultraviolet picosecond laser is used to focus a very small spot, which enables very fine processing during grooving. The heat-affected zone generated by the ultraviolet picosecond laser grooving is extremely small, and the material at the edge of the grooving will not melt, solidify, oxidize, etc. due to heat, thereby maintaining the original performance and structural integrity of the material.

[0025] The parameters are set as follows: scanning spacing 0.01-0.05mm, filling angle 0-45°, progressive angle 90-135°, power factor 30-95%, laser frequency 300-1000KHz, engraving speed 100-2000mm / min, and engraving times 1-10 times.

[0026] In the present invention, by adjusting the laser conditions, the minimum spacing of the grooves can be reduced to no more than 0.1 mm, thereby improving the cutting quality and the grooving accuracy.

[0027] Furthermore, between steps S2 and S3, a first cleaning is required, wherein the first cleaning is performed by horizontal wet cleaning or grinding or sandblasting or brushing, and the process is: board entry → degreasing → pickling → brushing or sandblasting or brushing → ultrasonic immersion → drying → board exit, wherein there are multi-stage water washing treatments between each link.

[0028] Furthermore, in step S3, the copper deposition process is: board entry → alkaline degreasing → roughening → pre-preg → activation → degumming → copper deposition → pickling → board exit; wherein, there are multi-stage water washing treatments between each link;

[0029] The process of electroplating is: degreasing → cleaning → acid immersion → electroplating → cleaning → drying;

[0030] The copper deposition parameters are: copper ion concentration of 2.2-3.8 g / L, temperature of 20-50° C., copper deposition time of 10-60 min, the electroplating solution includes copper sulfate and sulfuric acid, and the electroplating solution contains chloride ions, wherein the chloride ions serve as auxiliary gloss agent and copper gloss agent.

[0031] Furthermore, the mass concentration of the sulfuric acid is 150-200 g / L, the mass concentration of copper sulfate is 60-85 g / L, and the volume concentration of chloride ions is 3-5 ml / L.

[0032] Furthermore, in step S4, making the circuit pattern mainly includes the following steps:

[0033] 4.1 Film pasting: The dry film process is used for film pasting, wherein the thickness of the dry film is 40-80μm and the hot pressing temperature is 100-120℃;

[0034] 4.2 Exposure: Use film or LDI for exposure, and the exposure energy is measured according to the dry film exposure parameters and the exposure ruler;

[0035] 4.3 Development: The sodium carbonate system is used for development, wherein the concentration of sodium carbonate is 1% and the development temperature is 28-32°C;

[0036] 4.4 Etching: Etching is performed using a hydrochloric acid and sulfuric acid system, wherein the etching temperature is 40-50°C;

[0037] 4.5 Stripping: Use sodium hydroxide system for stripping, where the stripping temperature is 40-55℃;

[0038] Furthermore, in step S5, the solder resist process uses photosensitive ink. There is no special requirement for the solder resist process. In the embodiment of the present invention, the process uses direct printing by a printer.

[0039] The present invention uses the sensitivity of the photosensitive ink to light to enable it to accurately form a pattern during the exposure process, and the use of the photosensitive ink can ensure the insulation between the circuits and the accuracy of welding.

[0040] Furthermore, in step S6, the cleaning is a second cleaning. There are many ways to clean the second time. In the present invention, a spraying method is selected, wherein the spraying pressure is 1-2 kg / cm 2 The second cleaning solution is mainly a sulfuric acid solution with a mass concentration of 6-10%, and the cleaning temperature is 20-40°C.

[0041] The present invention also provides a Mini-LED package BT substrate, and the BT substrate is prepared by the above-mentioned BT substrate manufacturing method.

[0042] The groove width of the Mini-LED package BT substrate provided by the present invention can be no more than 0.1 mm, and the grooving accuracy is high, which improves the yield and efficiency of the subsequent Mini-LED packaging process.

[0043] Compared with the prior art, the present invention has the following advantages.

[0044] In the present invention, a dense light-absorbing film layer is formed by processing the surface of the BT carrier board; then the non-required area is removed by laser to realize the grooving of the LED package BT substrate, and the groove width can be no more than 0.1mm. The present invention forms a dense light-absorbing film layer, whose light absorption energy is increased, the cutting speed is fast, and ablation is not performed at the same position, thereby improving the cutting quality and reducing the burning of the BT layer by the laser, so as to avoid the excessive roughness of the groove wall caused by the shrinkage or protrusion of the resin, thereby improving the grooving accuracy and reducing the production cost, thereby realizing high-precision and low-cost grooving production. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0046] Figure 1 This is the location diagram of the laser slotting of the BT carrier board;

[0047] Figure 2 This is a schematic diagram of BT substrate plating;

[0048] Figure 3 This is a schematic diagram of the product structure of the BT substrate;

[0049] Figure 4 This is a diagram of the BT substrate of Example 1;

[0050] Figure 5 This is a diagram of the BT substrate of Comparative Example 1. DETAILED DESCRIPTION

[0051] 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 field without creative work are within the scope of protection of the present invention.

[0052] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", "fourth", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0053] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The BT board selected in this embodiment is a BT copper clad board, and the laser is an ultraviolet picosecond laser.

[0054] Example 1

[0055] This embodiment discloses a method for manufacturing a BT substrate for LED packaging, comprising the following steps:

[0056] S1, treating the surface of the BT copper clad laminate 1 to form a dense light absorbing film layer on the surface;

[0057] In this step, the method for surface treatment of the BT copper clad laminate 1 is as follows: first, the BT copper clad laminate 1 is placed at 200°C in a nitrogen atmosphere, and oxygen with a volume fraction of 10% is continuously introduced to form a copper oxide layer on its surface; then, a black coating is applied to the surface of the copper oxide layer, and a light-absorbing layer is formed after drying; finally, the surface of the light-absorbing layer is browned to form a dense light-absorbing film layer.

[0058] S2. Laser groove the surface treated BT substrate

[0059] In this step, the ultraviolet picosecond laser is turned on and the laser temperature is constantly controlled within 25±5°C; Figure 1 Laser grooving is performed at the position to remove the unnecessary area 2 and form a laser removal channel 3; wherein the laser spot size is adjusted to 10 μm; in this embodiment, the laser process parameters are set as follows: scanning spacing 0.01 mm, filling angle 10°, progressive angle 90°, power factor 30%, laser frequency 300 KHZ, engraving speed 1000 mm / min, and engraving times 5 times.

[0060] S3, electroplating copper on the slotted BT substrate to form a plating layer 4, and obtaining a slotted and electroplated BT substrate, such as Figure 2 As shown, in this step, the BT carrier board after laser grooving is placed in a copper plating solution, and the copper plating reaction is carried out at 50°C for 15 minutes. After the copper plating reaction is completed, the BT carrier board is electroplated for 45 minutes by an electroplating device to form an electroplating solution in which the mass concentration of sulfuric acid in the copper plating solution is 150g / L, the mass concentration of copper sulfate is 60g / L, and the volume concentration of chloride ions is 3ml / L.

[0061] S4, making circuit patterns on the BT carrier board after copper deposition;

[0062] In this step, a pattern electroplating process may be used to form a circuit pattern, and the specific process may include: film pasting-exposure-development-etching-film removal;

[0063] 4.1 Film pasting is to paste a dry film on the surface of the second plate with a thickness of 40μm and a hot pressing temperature of 100℃;

[0064] 4.2 Exposure, using film exposure;

[0065] 4.3 Development, which is to place the whole after the above steps in a developer to remove the dry film that has not undergone photopolymerization reaction, and define the circuit pattern on the surface of the remaining dry film;

[0066] 4.4 Etching: Etching in hydrochloric acid and sulfuric acid system, the etching temperature is 40°C;

[0067] 4.5 Defilming: Use sodium hydroxide system to remove dry film, and the film removal temperature is 40℃;

[0068] S5, performing solder mask treatment on the BT carrier board with the completed circuit pattern;

[0069] In this step, the solder resist treatment is to form a solder resist layer on the circuit pattern to protect the circuit pattern. The solder resist treatment is to directly print photosensitive ink using a printer, wherein the printing pressure is 0.2 MPa, the printing thickness is 15 μm, the pre-bake temperature is 70°C, the exposure energy is 400 m, and the curing temperature is 120°C.

[0070] S6, the BT substrate treated with solder mask is treated with nickel-palladium-gold to obtain a second plating layer 5, and then cleaned, cut, sliced, and inspected to obtain a Mini-LED package BT substrate, denoted as A1. Figure 3 and Figure 4 shown.

[0071] In this step, the BT substrate treated with solder mask is treated with nickel-palladium-gold, and the steps are: nickel-plating → palladium-plating → gold-plating, where the nickel-plating and gold-plating principles are the same as those in nickel-plating and gold-plating (not described one by one), and this embodiment adds a layer of palladium between nickel and gold. The specific process is:

[0072] Nickel-palladium-gold: pre-treatment → degreasing → → micro-etching → pre-impregnation → activation → post-impregnation → nickel-plating → palladium-plating → gold-plating. There are multi-level water washing treatments between each link of the above processes.

[0073] The palladium principle is Pd 2+ +2e - =Pd, the released electrons reduce the palladium ions, wherein the pH value of the palladium solution is 7-8 and the temperature is 40°C.

[0074] Example 2

[0075] This embodiment discloses a method for manufacturing a BT substrate for LED packaging, comprising the following steps:

[0076] S1. Treat the surface of the BT copper clad laminate to form a dense light-absorbing film layer on the surface;

[0077] In this step, the method for surface treatment of BT copper clad laminate is as follows: first, place the BT copper clad laminate at 200°C in a nitrogen atmosphere, and continuously introduce 30% oxygen by volume to form a copper oxide layer on the surface; then, coat the surface of the copper oxide layer with a dark light-absorbing material, wherein the light-absorbing material in this embodiment may be a black paint, which is dried to form a light-absorbing layer; finally, the surface of the light-absorbing layer is browned or blackened to form a dense light-absorbing film layer.

[0078] S2. Laser groove the surface treated BT substrate

[0079] In this step, the ultraviolet picosecond laser is turned on, and the laser temperature is constantly controlled within 25±5°C; the processing file is converted according to the product drawing; the laser spot size is adjusted to 80μm; in this embodiment, the laser process parameters are set as follows: scanning spacing 0.05mm, filling angle 45°, progressive angle 135°, power factor 95%, laser frequency 1000KHz, engraving speed 2000mm / min, and engraving times 10 times.

[0080] S3, electroplating copper on the slotted BT carrier to form a plating layer 4, thereby obtaining a slotted and electroplated BT carrier;

[0081] In this step, the laser grooved BT substrate is placed in a copper plating solution, and the copper plating reaction is carried out at 50°C for 15 minutes. After the copper plating reaction is completed, the BT substrate is electroplated for 45 minutes by an electroplating device, wherein the mass concentration of sulfuric acid in the copper plating solution is 200g / L, the mass concentration of copper sulfate is 85g / L, and the volume concentration of chloride ions is 5ml / L.

[0082] S4, making circuit patterns on the BT carrier board after copper deposition;

[0083] In this step, a pattern electroplating process may be used to form a circuit pattern, and the specific process may include: film pasting-exposure-development-etching-film removal;

[0084] 4.1 Film pasting is to paste a dry film on the surface of the BT substrate after copper deposition, with a thickness of 80μm and a hot pressing temperature of 120℃;

[0085] 4.2 Exposure, using film LDI exposure;

[0086] 4.3 Development, which is to place the whole after the above steps in a developer to remove the dry film that has not undergone photopolymerization reaction, and define the circuit pattern on the surface of the remaining dry film;

[0087] 4.4 Etching: Etching in hydrochloric acid and sulfuric acid system, etching temperature is 50℃

[0088] 4.5 Defilming: Use sodium hydroxide system to remove dry film, and the film removal temperature is 55℃.

[0089] S5, performing solder mask treatment on the BT carrier board with the completed circuit pattern;

[0090] In this step, the solder resist treatment is performed on the circuit pattern to form a solder resist layer to protect the circuit pattern. The solder resist treatment printer prints photosensitive ink, wherein the printing pressure is 0.3 MPa, the printing thickness is 25 μm, the pre-baking temperature is 80°C, the exposure energy is 500 m, and the curing temperature is 150°C.

[0091] S6. The BT substrate that has been treated with solder mask is treated with nickel-palladium-gold, and then cleaned, cut, sliced, and inspected to obtain a Mini-LED package BT substrate, which is recorded as A2.

[0092] In this step, the BT substrate treated with solder mask is treated with nickel-palladium-gold to form a second plating layer, and the steps are: nickel plating → palladium plating → gold plating, wherein the nickel plating and gold plating principles are consistent with the nickel plating and gold plating in nickel plating and gold plating (not repeated here), and this embodiment adds a layer of palladium between nickel and gold, and the specific process is as follows:

[0093] Nickel-palladium-gold: pre-treatment → degreasing → → micro-etching → pre-impregnation → activation → post-impregnation → nickel-plating → palladium-plating → gold-plating. There are multi-level water washing treatments between each link of the above processes.

[0094] The palladium principle is Pd 2+ +2e - =Pd, the released electrons reduce the palladium ions, wherein the pH value of the palladium solution is 7-8 and the temperature is 45°C.

[0095] Comparative Example 1

[0096] The slots are cut by die processing, and then the Mini-LED package BT substrate is made, which is denoted as B1. Figure 5 shown.

[0097] Comparative Example 2

[0098] Referring to Example 1, the difference from Example 1 is that the surface of the BT carrier board is not processed, and laser grooving is directly performed to obtain a Mini-LED package BT substrate, which is recorded as B2.

[0099] Comparative Example 3

[0100] Referring to Example 1, the difference from Example 1 is that the surface of the BT carrier is not subjected to oxidation treatment to obtain a Mini-LED package BT substrate, which is denoted as B3.

[0101] Comparative Example 4

[0102] Referring to Example 1, the difference from Example 1 is that no black paint is applied when the surface of the BT carrier is processed, and a Mini-LED package BT substrate is obtained, which is recorded as B4.

[0103] Comparative Example 5

[0104] Referring to Example 1, the difference from Example 1 is that only the surface of the BT carrier board is browned to obtain the Mini-LED package BT substrate B5.

[0105] Performance testing and evaluation

[0106] The groove widths of the Mini-LED package BT substrates A1-A2 prepared in this embodiment and the Mini-LED package BT substrates B1-B4 prepared in comparative examples 1-4 were tested, and the results are recorded in Table 1.

[0107] 50 Mini-LED package BT substrates A1-A2 prepared in Examples 1-2 and 50 Mini-LED package BT substrates B1-B4 prepared in Comparative Examples 1-4 were packaged into Mini-LED, and then the yield rate of the packaging process was tested. The results are recorded in Table 1.

[0108] Table 1

[0109]

[0110]

[0111] It can be seen from the data in Table 1 that the groove width of the Mini-LED package BT substrate prepared in Example 1 and Example 2 is no more than 0.1 mm, and the yield rate of the packaging process is high, indicating that the manufacturing method of the Mini-LED package BT substrate provided by the present invention can improve the grooving accuracy.

[0112] By comparing the data of Example 1 and Comparative Example 1, it can be seen that when the traditional die processing method is used for slotting, the processing accuracy is low, the minimum processing spacing is too large, and the yield rate of the packaging process is low.

[0113] By comparing the data of Example 1 and Comparative Examples 2-4, it can be seen that without surface treatment or only one-step surface treatment is performed, the groove width of the Mini-LED package BT substrate obtained is larger than that in Example 1, and the yield rate of the packaging process is lower than that in Example 1. The present invention prepares an oxide layer, lays a light-absorbing material on the oxide layer, and finally performs browning or blackening to form a dense light-absorbing film layer, which can further improve the light-absorbing effect of the surface layer, thereby increasing the cutting speed and improving the cutting quality.

[0114] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for manufacturing a Mini-LED package BT substrate, characterized in that: The following steps are involved: S1. Treat the surface of the BT carrier board to form a dense light-absorbing film layer on the surface; S2, laser grooving the surface treated BT substrate; S3, electroplating copper on the slotted BT substrate; S4, making circuit patterns on the BT carrier board after copper deposition; S5, performing solder mask treatment on the BT carrier board with the completed circuit pattern; S6. Perform nickel-palladium-gold deposition on the BT substrate that has been treated with solder mask, and then clean, cut, slice and inspect to obtain the Mini-LED package BT substrate.

2. The method according to claim 1, characterized in that: The method for treating the surface of the BT carrier board is as follows: oxidizing the surface of the BT carrier board to form a dense oxide film on its surface, laying a light-absorbing material on the surface of the oxide film to form a light-absorbing layer after drying, and finally browning or blackening the surface of the light-absorbing layer to form a dense light-absorbing film layer.

3. The method according to claim 1, characterized in that: The BT carrier board is one of a BT copper-clad board, a BT aluminum-clad board, a gold-plated BT board, a silver-plated BT board or a copper-plated BT board.

4. The method according to claim 1, characterized in that: In the step S2, the laser used for laser grooving is one of an ultraviolet picosecond laser, a solid-state laser, a semiconductor laser, a gas laser, an excimer laser or a fiber laser.

5. The method according to claim 1, characterized in that: In step S3, the parameters of copper deposition are: the concentration of copper ions is 2.2-3.8 g / L, the temperature is 20-50° C., and the copper deposition time is 10-60 min; The electroplating solution includes copper sulfate and sulfuric acid, and the electroplating solution contains chloride ions.

6. The method according to claim 5, characterized in that: The mass concentration of the sulfuric acid is 150-200 g / L, the mass concentration of the copper sulfate is 60-85 g / L, and the volume concentration of the chloride ion is 3-5 ml / L.

7. The manufacturing method according to claim 1, characterized in that: The production process of the circuit pattern in step S4 is: film pasting-exposure-development-etching-film stripping.

8. The manufacturing method according to claim 1, wherein in step S5, the solder resist treatment uses photosensitive ink.

9. The manufacturing method according to claim 1, characterized in that: In step S6, the cleaning solution is a sulfuric acid solution with a mass concentration of 6-10%, and the cleaning temperature is 20-40°C.

10. A BT substrate manufactured by the manufacturing method according to any one of claims 1 to 9, characterized in that: The groove width of the BT substrate is no greater than 0.1 mm.

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